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This one layer mint chocolate cake is reminiscent of a thin mint cookie! The recipe comes from Rebecca Firth’s cookbook The Cake Book and is truly a dessert masterpiece complete with rich chocolate cake, mint cream frosting, and glossy dark chocolate ganache to finish it all off.

top of a ganache frosted chocolate cake

You’re going to fall in love with this cake.

But first, let me share the source of this outstanding recipe. Do you follow Rebecca Firth from the blog Displaced Housewife? Rebecca is a best-selling author and flavor genius who imparts her creativity in every single recipe she publishes. She’s the source of these orange butter cookies, a recipe I shared from her 1st cookbook The Cookie Book. Rebecca is so much fun to follow because she tells us to “bake like a boss!” Plus, her photography is stunning, her recipes are unique and craveable, and she is truly as sweet as her vanilla chocolate chip cookies.

Rebecca, you’re such a delight!!


The Cake Book!

Rebecca Firth’s latest book is The Cake Book and I am so excited to share one of her recipes. Rebecca says that every occasion is better with cake and I know everyone reading this probably agrees! The Cake Book is filled with 60 fun and unique cake recipes divided into 8 chapters. Every single recipe includes a photo, cup & gram measurements, and thorough instructions. Some recipes I’m eager to try next include Raspberry Jam Coffee Cake, Chocolate Stout Cake with Champagne Buttercream, Dulce de Leche Pumpkin Cheesecake, and Lemon Olive Oil Chiffon Cake. Read more about The Cake Book here!

chocolate cake with sweet mint buttercream and dark chocolate ganache

Mint Chocolate Cookie Cake Details

Rebecca calls this indulgent dessert her Thicc Mint Cookie Cake. I include the word “chocolate” in the title just in case you come here searching for a chocolate cake. This cake is reminiscent of a thin mint cookie, which is why Cookie is in the title. But, you see, it’s not thin at all… it’s THICCCCCCK! The cake is a 1 layer 9-inch moist chocolate cake topped with peppermint cream frosting and mega glossy dark chocolate ganache. Eat your heart out!

  • Flavor: Enjoy dark, rich chocolate cake with peppermint frosting, and dark chocolate ganache on top. If you love mint and chocolate, you’d be a fool to skip this stunner.
  • Texture: This special single layer chocolate cake is as moist as my layered chocolate cake. What I love about Rebecca’s recipe, though, is that it’s made with both oil and butter. The combination of fats add plenty of moisture (oil) AND flavor (butter). I also find this cake isn’t as light and sponge-y as the layered chocolate cake, so you’ll enjoy a tighter crumb in each forkful.
  • Ease: There’s 3 components to this recipe and you can work on each as others are baking/cooling/setting up. There aren’t any specialty tools required, but a double boiler is handy for the ganache. If you don’t have a double boiler, use a heat-safe bowl over a saucepan of simmering water. Assembly and decorating is a breeze, which is something I always appreciate with one layer cakes!

Cake Batter Key Ingredients

Besides some basics like eggs, flour, sugar, baking powder & soda, and salt, here are some key ingredients you need for the cake batter.

  1. Butter: I love that Rebecca’s cake calls for both butter and oil. As mentioned above, you get rich flavor and moisture from both.
  2. Olive Oil: Use your extra virgin olive oil in this cake. If it’s something you like to cook with, it’s something you want to use in this recipe. If you don’t have olive oil, I’m sure you could use vegetable oil.
  3. Vanilla Extract: Rebecca is no stranger to vanilla extract and she loves using plenty in her delicious recipes. You need vanilla extract for the cake batter AND the chocolate ganache on top. Make sure you pick up some peppermint extract for the mint cream layer, too.
  4. Cocoa powder: Rebecca’s recipe calls for dutch process cocoa. I accidentally used natural cocoa the 1st time I made it, then I made it again with dutched. Both cakes were amazing! You could use either in this recipe.
  5. Hot Water: Hot water is the very last ingredient in the cake batter. Have you made my layered chocolate cake before? That recipe also calls for hot liquid (water or black coffee). Hot liquid enhances cocoa powder’s flavor and also encourages it to bloom and dissolve appropriately.

Below, right: Take a look at the photo below on the right. That’s creamed butter + sugar + olive oil. Make sure you cream the butter and sugar together first, and then mix in the olive oil.

sugar, cocoa powder, butter, and other ingredients shown next to creamed butter, sugar, and oil mixture

Let me show you the cake batter before and after adding the hot water. On the left below, notice the thick batter. On the right below, the batter has thinned out after adding the hot liquid.

chocolate cake batter before and after adding hot water to the batter

Bake the cake in a 9-inch round cake pan:

single layer chocolate cake before and after baking

If you’re looking for smaller 6-inch cake, this 1 layer 6-inch chocolate cake is a favorite.


Finishing the Mint Chocolate Cookie Cake

This cake wouldn’t be THICK without our layered toppings:

  1. Peppermint Cream: The thick layer of peppermint frosting reminds me of the filling between oatmeal creme pies, only with a mint flavor. The peppermint cream uses a combination of butter and shortening for flavor and stability. You also need peppermint extract AND real mint for flavor. Save a few mint leaves for garnish, if desired.
  2. Ganache: Start the chocolate ganache as the cake cools because by the time the cake has cooled, the ganache will be ready too. Rebecca’s ganache uses *slightly* more chocolate than cream, so it’s wonderfully thick. (Thinner chocolate ganache uses a 1:1 ratio.) Use 2 cups of chopped dark chocolate, which is about 3 4-ounce chopped baking chocolate bars (such as Ghirardelli or Bakers brand). A little salt and vanilla add flavor to her ganache. I actually reduced the salt in the ganache the 2nd time I made it because I used intense dark chocolate– see my recipe note below.

Both toppings yield a lot of volume and don’t be afraid to use it all!

mint buttercream in glass bowl and on top of chocolate cake
chocolate ganache in double boiler and shown again poured on frosted cake
1 layer chocolate cake with mint buttercream and drip ganache on top
slice of chocolate 1 layer cake with mint buttercream and chocolate ganache on top

I hope you enjoy this show-stopping cake and if you have a moment, check out Rebecca’s new cookbook. I know many of you love finding new cake recipes!

Print
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top of a ganache frosted chocolate cake

Mint Chocolate Cookie Cake

  • Author: Sally
  • Prep Time: 30 minutes
  • Cook Time: 35 minutes
  • Total Time: 3 hours (includes cooling)
  • Yield: serves 810 1x
  • Category: Dessert
  • Method: Baking
  • Cuisine: American

Description

This mint chocolate cookie cake will remind you of a thin mint cookie, only it’s not thin… it’s mega thick! The show stopping cake, complete with peppermint cream and glossy chocolate ganache, comes from Rebecca Firth’s cookbook The Cake Book.


Ingredients

Scale

Cake

  • 1 cup (200g) granulated sugar
  • 1/2 cup (8 Tbsp; 113g) unsalted butter, room temperature and cut into 8 pieces
  • 1/4 cup (56g) extra-virgin olive oil
  • 2 large eggs, at room temperature
  • 1 Tablespoon (13g) pure vanilla extract or vanilla paste
  • 1 cup (135g) all-purpose flour
  • 1/2 cup (43g) unsweetened dutch-process or natural cocoa powder, sifted
  • 1 teaspoon (5g) baking powder
  • 1 teaspoon (5g) baking soda
  • 1 teaspoon (6g) salt or fine sea salt
  • 1/2 cup (120ml) hot water

Chocolate Ganache

  • 2 cups (340g) dark chocolate, finely chopped* (see note)
  • 1 and 1/4 cups (300ml) heavy cream or heavy whipping cream
  • 1/4 teaspoon salt or fine sea salt*
  • 2 teaspoons (8g) pure vanilla extract or vanilla paste

Peppermint Cream

  • 1/2 cup (8 Tbsp; 113g) unsalted butter, room temperature
  • 1/2 cup (113g) vegetable shortening, room temperature*
  • 2 Tablespoons (4g) fresh mint, finely chopped (plus more for garnish if desired)
  • 3 and 1/2 cups (420g) confectioners’ sugar
  • 2 teaspoons (8g) peppermint extract
  • 3 Tablespoons (45ml) whole milk, room temperature

Instructions

  1. Preheat oven to 350°F (177°C). Grease a 9×2 inch round cake pan, line with a parchment paper round (see #6 in Cake Baking Tips), and then lightly grease the parchment paper. Parchment paper helps the cake seamlessly release from the pan. I recommend using nonstick spray for greasing.
  2. For the cake: In the bowl of an electric handheld or stand mixer fitted with a paddle attachment, cream the sugar and butter together on medium speed until light and fluffy, about 4-5 minutes. With the mixer on low, slowly stream in the oil. Scrape the sides and bottom of the bowl to make sure everything is well blended. With the mixer on low, add in the eggs, one at a time, making sure that each is incorporated before adding in the next. Add the vanilla and run the mixer for 30 more seconds. Take the bowl out of the mixer.
  3. In a medium bowl, whisk the flour, cocoa powder, baking powder, baking soda, and salt until combined. With a rubber spatula or wooden spoon, fold the flour mixture into the butter mixture in three batches, mixing each until almost blended. Batter will be very thick. Finally, pour in the hot water and whisk to combine. Pour evenly into prepared cake pan. Lightly tap pan on the counter a few times to settle the cake batter and release any trapped air bubbles.
  4. Bake in the center of the oven for 30-36 minutes (and up to 40 minutes, if needed but begin checking at 30). The cake is done when a toothpick inserted into the center comes out clean or when the cake springs back if you lightly poke the center with your finger. Remove from the oven and cool cake in the pan set on a cooling rack for 20 minutes. Remove cake from the pan and place cake directly on the cooling rack to finish cooling. Once cool, you can place the cake on your cake stand or serving plate.
  5. Make the ganache as the cake cools: Place the chocolate, cream, and salt in a large heat-safe bowl set over a medium saucepan of simmering water. (Or use a double boiler if you have one.) Do not let the bottom of the bowl touch the water. Stir frequently until chocolate has melted and ganache is smooth. Remove from heat and stir in the vanilla. Set aside at room temperature to cool until thickened. You want it cool enough to not melt the frosting, but still a little fluid. This takes about 60-90 minutes to cool. (NOTE: This yields a lot of ganache and I used about 3/4 of it on top of the cake and then drizzled more on each slice.)
  6. For the peppermint cream frosting: In the bowl of an electric handheld or stand mixer fitted with a paddle attachment, beat the butter, shortening, and mint together on medium-low speed until combined. Scrape down the sides and up the bottom of the bowl and beat again as needed to combine. Add confectioners’ sugar, peppermint extract, and milk and continue beating until whipped, smooth and creamy.
  7. Assemble: Spread peppermint cream in a thick layer all over the top of the cooled cake. There’s a lot of frosting, so pile it high. Try to make the edges sharp angles that follow the line of the cake. (You can see it pictured above.) I always use a small icing spatula. Place uncovered in the refrigerator for 30 minutes to help set the frosting. Pour ganache slowly on top of cake and use a small offset spatula or a knife to gently spread all over the frosting. Return cake to the refrigerator and chill uncovered for 30 minutes before slicing and serving. Feel free to garnish with mint leaves.
  8. Cover leftover cake tightly and store in the refrigerator for up to 1 week.

Notes

  1. Make Ahead & Freezing Instructions: Prepare cake through step 4. Wrap the baked and cooled cake tightly and keep at room temperature for 1 day or freeze up to 3 months. Bring to room temperature (if frozen) then continue with step 5. Peppermint frosting can also be made 1 day ahead of time. Cover tightly and refrigerate overnight. Bring frosting to room temperature, and then beat the frosting on medium speed for a few seconds so it’s creamy again. Adding a splash of milk will help thin the frosting out, if needed. You can also make the ganache 1 day in advance and cover and refrigerate, but you may need to slightly warm it again over a stove so it’s slightly fluid again. Assembled/frosted cake freezes well, up to 3 months. Thaw overnight in the refrigerator, and then bring to room temperature or serve cold. See How to Freeze Cakes.
  2. Chocolate in Ganache: You can use 2 cups of high quality dark chocolate chips or 3 4-ounce chocolate baking bars that you can find in the baking aisle such as Ghirardelli or Bakers brand. Semi-sweet or dark chocolate is fine.
  3. Salt in Ganache: I used 70% dark chocolate baking bars (found in the baking aisle), so I reduced the salt in Rebecca’s recipe. If using very dark chocolate, you may want to keep the amount at 1/4 teaspoon. If using a sweeter chocolate, feel free to use 1/2 teaspoon as her recipe calls for.
  4. Shortening: If you do not have shortening, you can replace with the same amount of room temperature unsalted butter for a total of 1 cup (226g) butter in the peppermint frosting.
  5. Recipe with permission from The Cake Book by Rebecca Firth

Keywords: mint chocolate cake

Reader Questions and Reviews

  1. If you love chocolate mint, this cake is for you! The chocolate cake is very moist. The amount of mint flavor, in the peppermint cream, is perfect. It’s gentle, but present. The fresh mint adds a particular freshness to the cream. The ganache is great. I melted a dark chocolate Lindt chocolate bar along with the whip cream and it was amazing. Once the cake was assembled, I used left over Royal Icing to add a white drizzle on top of the ganache before garnishing the cake with a fresh mint leaf. https://sallysbakingaddiction.com/royal-icing/
    All around, it was a wonderful dessert for my family and dinner guests.

  2. I just made this recipe yesterday and it was outstanding!! Mine even looked like the picture.

    I’m wondering why sometimes ganache is made in a double boiler and other times the heavy cream is poured into the chopped chocolate? Does it have to do with using chocolate chips instead of baking bars? If so, how do you determine what method is best for each recipe? Just wondering for my own experiments!

    Thank you for ALL of the amazing recipes!!

    1. Hi Emilee, I’m so glad that you made and enjoyed this cake recipe. We all LOVED it! There is really no rhyme or reason why some make ganache one way and others make ganache another way. I personally love to make it by warming the cream and pouring it over the chocolate. This method works best with pure baking chocolate. Here Rebecca says chocolate chips are perfectly fine and maybe that’s why melting them with the heavy cream works so well!

    1. Hi Moe, we haven’t tested that substitution. Butter would definitely work!

  3. Hi, this cake looks delicious and I can’t wait to try it. What do you think about substituting the half cup of hot water for half a cup of coffee, to add to the flavour of the cake? Thank you for sharing this recipe.

  4. Made this for my fiance’s birthday, and it was delicious!

  5. Hi,
    Can this be made into a sheet cake?? I want to number two cut out cake for a birthday cake this week, will cake work for that?
    Thank you so so so much!!

    1. Hi Sienna! For a chocolate sheet cake, we recommend our triple chocolate cake recipe – it’s the right amount of batter. We would use the sour cream version detailed in the recipe notes for a sturdier crumb. Let us know how it goes!

  6. I’m thinking of doing mint chocolate whoopie pies for St. Patrick’s Day- would you say this mint cream or your mint chocolate chip frosting would make a better filling?

    1. Hi Deb! Either would definitely work, but the mint chip frosting is a favorite – let us know what you try!

  7. I made this yesterday for an early St. Patrick’s Day dinner. We all loved it! Even though it has 3 separate components, each one is fairly easy to make. Definitely a keeper!

  8. Terrific recipe! Made this for a family gathering yesterday and it was a big hit. My granddaughters (11 through 16) are my severest critics – they pull no punches – and it passed their test. Several are Girl Scouts – this is right at the end of GS cookie sale season – and they had a lot fun with the thin mint cookie theme. This was a fun cake to bake (it’s recreation for me) with good results so, I’ll make this again.

  9. Wow! A textural, visual, flavorful, masterpiece! Followed to a T.

  10. Made this and loved it. Was hoping to make for my mom, but doing a peanut butter cream as that is more her taste. Would your PB cream frosting (https://sallysbakingaddiction.com/peanut-butter-frosting/) work? Or would you recommend something else?

    1. Hi Meghan, that should work great! We’d love to know how it turns out for you.

  11. So I haven’t tried this recipe yet, but I’m planning on making it for my little sister’s twelveth birthday party. Could I make this a layer cake? How tall is the cake? I want there to be more than enough of this cake for her since she loves mint chocolate chip so much. I found this recipe and it just looks perfect for her. If there any way I could make this big enough? (BTW I had to use a friend’s email so she can send it to me)

    1. Hi Ava! We haven’t tested it, but you could try using our two layer triple chocolate cake recipe, with this peppermint cream in the middle of the layers. You could top with ganache, or buttercream, or both! Let us know what you try 🙂

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