Packed with peanut butter, chewy oats, and oodles of chocolate chips and M&M’s, these flourless monster cookies are simply unbelievable. I tried and tested this recipe multiple times over the past year, with various groups of taste testers, and, truly—no one believed there isn’t any flour.
No flour means more peanut butter flavor. Let’s do this!
Have you ever made big giant monster cookies, soft and thick monster cookies, or these big fat peanut butter oatmeal chocolate chip cookies before? They’re two reader (and personal!) favorites. Today’s cookies are a lot like those… but with less sugar, less butter, and—did I mention this?—no flour. Yet, magically, they’re somehow just as delicious.
Not one of the many very satisfied taste testers (including an entire tee-ball team!) missed the flour at all in these cookies!
What Are Monster Cookies?
The label soft and thick monster cookies refers to an all-in-one combination of several different types of cookies: a monster mash-up of peanut butter cookies, oatmeal chocolate chip cookies, and M&M cookies! Like Frankenstein’s monster, if Dr. Frankenstein were a baker. (And that would have been a very different story.) My recipe today is for flourless monster cookies.
Here’s What You’ll Love About These Flourless Monster Cookies
- Naturally gluten free, if using certified GF oats
- Chewy, peanut buttery, and loaded with chocolate chips and M&M’s
- Easy dessert recipe that doesn’t require a mixer
- Only 30 minutes of dough chilling time, so they can be ready in an hour!
Grab These Ingredients
- Oats: Old-fashioned whole rolled oats are the base for these chewy cookies. If needed, use certified GF oats to ensure the cookies are gluten free.
- Baking Soda: For a little lift, to counteract the weight of the peanut butter.
- Salt: Flavor enhancer/sweetness balancer.
- Butter: Just a little bit of melted butter goes a long way in adding delicious flavor and even more chewiness, just like in chewy chocolate chip cookies.
- Brown Sugar: Light brown sugar sweetens, and keeps the cookies moist.
- Eggs: These provide structure and richness, while binding all the ingredients together.
- Vanilla Extract: Another key flavor enhancer in most cookie recipes. You can use homemade vanilla extract or store-bought, either works!
- Peanut Butter: I recommend using creamy processed peanut butter for this recipe, like Jif or Skippy. Whether you’re making these cookies, peanut butter blossoms, peanut butter fudge puddles, or really any peanut butter-based cookies, processed creamy peanut butter will give you the best taste and soft-baked texture.
- M&M’s: You can use either mini or regular-size M&M’s in these cookies. I like to use the color-themed holiday edition M&M’s if I’m making these for a holiday or party.
- Chocolate Chips: Because, obviously.
Expect a Gooey, Sticky Cookie Dough
The cookie dough comes together in 2 bowls—one for the wet ingredients, and one for the dry ingredients. Then stir everything together with a silicone spatula. It may take a bit of arm muscle, but it will come together. Finally, add the chocolate chips and M&M’s, folding them in with the spatula.
This is a gooey, sticky cookie dough. And, like many other cookie recipes I publish, refrigerating the dough before baking it helps ensure the cookies hold their shape. 30 minutes is plenty, which gives you just enough time to line your baking sheets, grab your cookie scoop, and preheat the oven. (Or, if you’re feeling ambitious, you can use the time to prepare and bake a no-chill recipe like shortbread cookies or coconut macaroons!)
**Chilling is one of my top tips for how to prevent cookies from overspreading.**
When you’re ready to bake, scoop mounds of cookie dough (a heaping 2 Tablespoons in size, about 45g each). A medium cookie scoop is helpful with the sticky dough, but make sure it is a heaping scoop to yield the proper amount of cookie dough. Then bake on a lined baking sheet until the edges are set. The centers will still look a bit soft, and that’s ok. Mine take about 14 minutes in the oven.
FAQ: Can I Make These Nut-Free?
Yes. The team & I tested these flourless monster cookies with sunflower seed butter in place of the peanut butter, and the recipe works. However, keep in mind that when sunflower seed butter and baking soda combine, there’s a natural reaction that causes the inside of the cookies to turn green! It’s harmless and doesn’t change the taste or texture. The kids loved it. 😉 (Now they’re really Dr. Frankenstein’s monster cookies!)
This recipe is part of my annual cookie countdown called Sally’s Cookie Palooza. It’s the biggest, most delicious event of the year! Browse dozens of cookie recipes over on the Sally’s Cookie Palooza page.
Flourless Monster Cookies
- Prep Time: 40 minutes
- Cook Time: 14 minutes
- Total Time: 1 hour
- Yield: 18–20 cookies
- Category: Cookies
- Method: Baking
- Cuisine: American
Description
Packed with peanut butter, chewy oats, and oodles of chocolate chips and M&M’s, these flourless monster cookies are a monster mash-up of favorite cookie types. I promise you won’t miss the flour at all! Be sure to refrigerate the sticky cookie dough for at least 30 minutes before shaping and baking.
Ingredients
- 1 and 1/2 cups (128g) old-fashioned whole rolled oats
- 1 teaspoon baking soda
- 1/8 teaspoon salt
- 3 Tablespoons (43g) unsalted butter, melted
- 2/3 cup (133g) packed light or dark brown sugar
- 2 large eggs, at room temperature
- 1 teaspoon pure vanilla extract
- 1 cup (250g) creamy peanut butter (see note)
- 1/2 cup (105g) regular-size M&M’s, or 1/3 cup (77g) mini M&M’s
- 1/3 cup (60g) semi-sweet chocolate chips
Instructions
- In a medium bowl, whisk the oats, baking soda, and salt together until combined. Set aside.
- In a large bowl, whisk the melted butter, brown sugar, eggs, and vanilla together until combined. Whisk in the peanut butter.
- Pour the dry ingredients into the bowl with the wet ingredients and mix with a silicone spatula until combined. (Takes some arm muscle!) Fold in the M&Ms and chocolate chips. The dough will be sticky and gooey.
- Cover the cookie dough tightly and chill in the refrigerator for at least 30 minutes and up to 3 days.
- Preheat oven to 350°F (177°C). Line large baking sheets with parchment paper or silicone baking mats.
- Scoop the dough, a heaping 2 Tablespoons (45g) each, and place the mounds of cookie dough about 3 inches apart on the prepared baking sheets. (A medium cookie scoop helps with the sticky dough, but make sure it is a heaping scoop to get you 2 Tablespoons (45g) of dough.)
- Bake until the edges are set and golden brown, about 12–15 minutes. The cookies will still look soft in the centers.
- Cool cookies for 10 minutes on the baking sheet. During this time, I like to press a few more chocolate chips or M&M’s into the tops of the warm cookies. (This is optional and only for looks.) Transfer to wire rack to cool completely.
- Cover leftover cookies tightly and store at room temperature for up to 1 week.
Notes
- Make Ahead & Freezing Instructions: You can make this dough ahead of time and keep it in the refrigerator for up to 3 days. Baked cookies freeze well for up to 3 months. Unbaked cookie dough balls freeze well for up to 3 months. Bake frozen cookie dough balls for an extra minute, no need to thaw. Read my tips and tricks on how to freeze cookie dough.
- Special Tools (affiliate links): Glass Mixing Bowls | Whisk | Silicone Spatula | Cookie Scoop | Baking Sheets | Silicone Baking Mat or Parchment Paper Sheets | Cooling Rack
- Oats: Oats are naturally gluten free, but if you have dietary restrictions, be sure they are labeled “certified gluten free” because oats can be packaged in a facility with gluten.
- Can I Use Quick Oats? You can certainly try it. The cookies will not spread as much, and you’ll lose some of the chewy texture.
- Peanut Butter: I strongly recommend using processed creamy peanut butter for these cookies, such as Jif or Skippy. Using natural peanut butter will make for a drier, more crumbly cookie.
- Nut-Free: We tested these cookies with sunflower seed butter in place of the peanut butter, and the recipe works; but keep in mind that when sunflower seed butter and baking soda combine, there’s a natural reaction that causes the inside of the cookies to turn green! It’s harmless and doesn’t change the taste or texture.
- Be sure to check out my top 5 cookie baking tips AND these are my 10 must-have cookie baking tools.
Reader Comments and Reviews
I made these for my 7 year old granddaughter who is GF and she LOVED them. She is very picky and there aren’t a lot of GF cookies she likes. As an added bonus, we froze some to have here when she comes, but my husband and I couldn’t stay out of them even when they were frozen. Gotta make more for the princess!
These were so yummy! And incredibly easy! Can’t wait to make them again.
This cookies are so good. Very delicious, just a few and common ingredients and very easy to do.
Love your recipes so much! Can I use GF Steel Cut Oats?? Having trouble finding GF Whole Grain Oats that are not Instant or Quick Cook!
Hi Pat, steel cut oats aren’t ideal here. You need regular rolled oats for this dough.
These have great flavor, but I did not like the texture…a little too soft. Even split reviews among the rest of the family. So I think I did miss the flour!
I made these veganish as I still used m&ms which have milk and they came out amazing! Instead of melted butter I substituted 1tbsp of melted vegan butter and 2tbsp of apple sauce and instead of eggs I did sparkling water I should have used 1/4 cup per egg but messed up and did 1tbsp per egg and they still came out delish. Everyone in my house was a huge fan!
Has anyone ever made these with a chia seed egg? I’m wondering if I could make these egg-free for someone with an egg allergy.
We haven’t tested that swap, Amanda, but let us know if you do!
Made these for my annual cookie swap and followed your suggestions to a “T” – including using my cookie scoop and making sure I had at least 2 Tbsp. of batter. They were a hit!
This recipe is awesome! We are GF and dairy free, so I subbed Country Crock Plant Butter for the butter, used organic raw peanut butter, and vegan dark chocolate chips and they came out amazing!
Could you use Dark Brown sugar instead of light brown? Thank you.
Absolutely.
These are delicious cookies. I’ve made them three times already because everyone likes them! However, they don’t last long enough to freeze
These look amazing. Do you have any advice for switching shortening to a dairy free option?
Hi Helen, we don’t recommend switching to shortening, but you might have luck with a plant-based butter instead. Let us know if you try it!
I ended up substituting Miyokos plant milk butter and they are delicious! My guess is that they would be chewier with real butter, but they are very good, and now my friend who is gluten and dairy free can enjoy them!
The cookies baked up perfectly. I tried one that had cooled on the rack and it had just a slight crunch and was softer inside. Yum! Then I put the batch in a container with a lid. Opened it about six hours later and the cookies were super soft with no crunch at all. Is that normal? Is there any way to get back a little of the crunch?
Hi Lisa, yes, that’s completely normal for these and a lot of soft-baked drop cookies. You can keep them lightly covered (lid partially open) and that will help.
Delicious and incredibly easy to make!
These cookies were so easy, festive and delicious! Made them with my 3 year old grandson, we both loved them. The only down side is, for us batter lovers, this raw dough is so darn good!
Used skippy creamy peanut butter and the cookies were excellent. You’re right, couldn’t tell these were flourless and different from regular monster cookies!
I doubled the recipe, but I think I forgot to double the butter. I’m hoping it will still turn out ok. The dough is marinating in the fridge now. I plan on keeping it in there for a couple of days. Crossing fingers they will still be yummy!
These were really dry! Tried cooking them less, but not sure what happened…
Delicious cookies!! Thank you for the gluten free option in your cookie emails! So glad I tried these.
This one didn’t do it for me. I flavour was delicious (can’t go wrong with peanut butter, oatmeal and chocolate) but the cookies overspread for me and the texture was not great. I followed the recipe to a T using the gram measurements for all the major ingredients but it was just lacking.
Can you use almond Butter? If so do you use same measurements?
Hi Annie, almond butter will work in place of the peanut butter, but the cookies will likely be a bit drier/crumblier. Please do let us know if you try them!
This is one of the best gluten free cookies I ever made! It’s chewy, festive, peanut butter, and chocolate what more can you ask for? Make this for the holiday!
I love all your recipes your great baker can I have more gluten free Xmas cookies please
Hi Michelle! You can find all of our gluten free recipe here. Quite a few cookie recipes there that you might enjoy, too!
Hi Sally, I can’t wait to make these as they sound delicious. But I’d like to omit the M&M’s. Will that change the texture of the cookies
Hi Rachel, you’ll miss the crunch from the M&Ms, but feel free to replace with more chocolate chips or another favorite add-in.
Good evening! My first batch was a bit dry. Flavor was good. Second batch I added cornstarch and sour cream. These were even better. Thanks for the great recipe!
My son can eat almond butter but not butter from seeds or other nuts. Your comment about using processed peanut butter makes me wonder about almond butter which is rarely processed. Does it work? Thank you. We loved your gluten free sugar cookies with the needed adaptations.
Hi E, almond butter will work in place of the peanut butter, but the cookies will likely be a bit drier/crumblier. Please do let us know if you try them!
This sounds like a cookie I’d like to try, but I have Jif Crunchy PB. Can I use crunchy instead of smooth if we like the peanut chunks? Or will that mess up something else?
Hi Patti, generally, chunky/crunchy PB is thicker. You can use it, but the cookies will not spread as much.
Can I use the regular quick cook oatmeal, which is what I have on hand.
Thanks Denise
Hi Denise, I’m sure you could. However, the cookies may not spread as much. You can try it, and try skipping the dough chilling (to help them spread). Let me know what you try!
Sally, is it possible to use quick cook oatmeal?
Would like to make these for the kids at the school I work for but they only carry the quick cook
Hi Sarah, you can definitely try it. The cookies may not spread as much.
Can I use quick oats for monster cookie recipe
Hi Anne, you can, but the cookies may not spread as much and you’ll lose some of that chewy texture. I haven’t tested it, but I wonder if you could skip the cookie dough chilling? Let me know what you try.