At first glance, these might look like ordinary oatmeal M&M cookies, but the secret surprise inside makes this dessert a game changer. Peanut butter cup surprise monster cookies are soft and chewy M&M-speckled oatmeal cookies filled with a creamy peanut butter cup.
Peanut butter + oats + M&Ms = monster cookies! But this peanut butter cookie dough is a little different from our original monster cookies. They’re a little closer to these peanut butter cup oatmeal cookies. The difference? For this recipe, we use all brown sugar to keep the cookies extra soft and flavorful.
Tell Me About these Peanut Butter Cup Surprise Monster Cookies
- Flavor: Peanut butter is front and center. You’ll love all the peanut butter flavor paired with chocolate from both the peanut butter cup and M&Ms.
- Texture: Thanks to the brown sugar, these cookies stay thick, soft, and extra chewy. Quick oats are responsible for the uniform texture. Make sure to use quick oats, NOT old-fashioned oats. Quick oats are smaller than old-fashioned oats and more finely ground. Tip: If you only have old-fashioned oats, just pulse them in your food processor a few times so they’re smaller. While regular M&M’s certainly work, we prefer the mini ones because you get more M&Ms in each monster bite.
- Ease: Start by making the easiest peanut butter cookie dough. Guess what? There’s no mixer required. And it gets better: there’s no dough chilling required either. The quicker you begin, the quicker you’ll be eating these peanut butter cup monster cookies.
- Time: No dough chilling makes this recipe one of the quickest and easiest cookies on our website. If you want cookies in a hurry, here are a few more time-saving cookie recipes that don’t require chilling. Snickerdoodles and shortbread cookies are two favorites!
How to Add the Peanut Butter Cup Surprise
At first it might seem intimidating to sandwich a peanut butter cup inside a cookie, but it’s super easy. Once you try it, you’ll be adding surprises to all your cookies, like we did with these salted caramel dark chocolate cookies and Reese’s stuffed peanut butter cookies.
Here’s the scoop. Literally.
- Scoop 1 Tablespoon of dough onto your baking sheet. Pat down the dough to flatten.
- Press a peanut butter cup into the top of the flattened cookie dough.
- Then scoop 1.5 Tablespoons of cookie dough and place on top and around the peanut butter cup. Make sure you seal the edges of the cookie. This will prevent the peanut butter cup from leaking out.
- Since this cookie dough only spreads slightly in the oven, you might need to help it along. Before you start baking, gently press down on the stuffed cookie dough balls to flatten them slightly. This gives them the little spreading “push” they need.
More Cookie Recipes To Discover
- Peanut Butter Cookie Sandwiches
- Brownie Cookies
- M&M Cookies or M&M Cookie Bars
- Chocolate Chip Cookies
- Oatmeal Chocolate Chip Cookies
Peanut butter monster cookies with a Reese’s peanut butter cup inside!!
- 3/4 cup (94g) all-purpose flour (spooned & leveled)
- 1/4 teaspoon salt
- 1/2 teaspoon baking soda
- 1/2 cup (8 Tbsp; 113g) unsalted butter, melted
- 1 cup (200g) packed light or dark brown sugar
- 1 large egg, at room temperature
- 1/2 cup (125g) creamy peanut butter (not natural style)
- 2 teaspoons pure vanilla extract
- 2 cups (170g) quick oats*
- 1 and 1/4 cups mini or regular size M&Ms
- 18 Reese’s miniature peanut butter cups, unwrapped
- Preheat oven to 350°F (177°C). Line 2 large baking sheets with parchment paper or silicone baking mats. (Always recommended for cookies.) Set aside.
- Toss the flour, salt, and baking soda together in a large bowl. Set aside.
- In a medium bowl, whisk the melted butter and brown sugar together until no brown sugar lumps remain. Whisk in the egg, then the peanut butter until combined. Finally, whisk in the vanilla. Pour the wet ingredients into the dry ingredients and mix together with a large spoon or silicone spatula. The dough will be very soft and slick. Fold in the oats and the M&Ms. Allow the cookie dough to sit for 15 minutes—the oats will absorb some moisture, making the dough easier to work with.
- You can use the photos above as visuals for this step. Take 1 Tablespoon of dough and slightly flatten out on the prepared baking sheet. Stick a peanut butter cup on top, as shown above. Top the peanut butter cup with 1.5 Tablespoons of cookie dough and seal down the sides so that the peanut butter cup is securely stuffed inside. You can pick it up and roll into a smooth ball if needed. Slightly flatten down the top as best you can (it can’t be totally flat because of the peanut butter cup inside). Repeat with the rest of the dough and peanut butter cups.
- Bake the cookies for 12-13 minutes. The cookies will look very soft. They will continue to bake on the cookie sheet. Remove from the oven and lightly press down on each cookie to slightly flatten (if they didn’t spread much in the oven). Allow to cool on the cookie sheet for 10 minutes before transferring to a wire rack to cool completely.
- Make Ahead Instructions: Cookies stay soft and fresh for 7 days at room temperature. Baked cookies can be frozen up to 3 months. You can freeze cookie dough balls by assembling as directed. Then chill in the refrigerator until firm and ready to pick up (you’re doing this because the cookie dough is so sticky). Once firm, freeze dough balls in ziplock bags. Bake as directed for 1-2 extra minutes, do not thaw. Read my tips and tricks on how to freeze cookie dough.
- Special Tools (affiliate links): Glass Mixing Bowls | Whisk | Silicone Spatula | Baking Sheets | Silicone Baking Mats or Parchment Paper | Cooling Rack
- Oats: I do not recommend using old-fashioned style oats (aka whole oats) in this cookie recipe. They are the large-cut oats. You need quick oats, which are more finely ground (and smaller) whole oats. I often only buy old-fashioned (whole oats) from the store. So for this recipe, I simply pulse whole oats in a food processor a few times to cut them down to “quick oat” size.
- Be sure to check out my top 5 cookie baking tips AND these are my 10 must-have cookie baking tools.
Keywords: peanut butter cup stuffed monster cookies, monster cookies