Craving monster cookies? This is the BEST monster cookie recipe I’ve ever made, and it comes straight from my Grandma LaDene. These jumbo monster cookies are chewy in the middle, slightly crisp at the edges, and loaded with peanut butter, oats, M&M’s and chocolate chips. And there’s no flour in them at all. They’re my go-to for bake sales, potlucks, cookie exchanges and movie nights, and the dough freezes beautifully, so you can bake a few at a time.
Why you’ll love these monster cookies
- Flourless: oats and peanut butter do all the work (gluten-free with certified GF oats)
- One bowl, about 27 minutes
- Big batch: 24 jumbo cookies
- Freezer-friendly dough and baked cookies
What Are Monster Cookies?
Monster cookies are four favorite cookies in one: peanut butter, oatmeal, chocolate chip and M&M cookies. Classic monster cookies use oats instead of flour, which gives them a hearty, chewy texture. They’re named for their size, and for the huge batches they were traditionally baked in. Many old family recipes called for a dozen eggs!
Why This Recipe Works
This recipe came from my Grandma LaDene, and I’ve never tasted a better, more perfectly baked cookie. She would bring these cookies over to our house wrapped individually in the same cardboard oatmeal container. They stacked perfectly in the container, and I secretly think wrapping and stacking them in that container would prevent us from eating several at a time. The cookies she made were huge, like 4-5″ in diameter, thus taking on the name, “monster” cookies for their sheer size.
- No flour needed. Peanut butter and oats give the cookies structure, so they bake up thick and chewy, never cakey.
- Creamed butter and sugar add tiny air pockets that keep jumbo cookies soft in the center.
- Jumbo size means crisp edges and a soft middle in every cookie.
Monster Cookie Ingredients
- Peanut Butter – use a creamy, no-stir brand like Jif or Skippy. Natural peanut butter separates and makes flourless cookies dry and crumbly. Crunchy works if you like bits of peanut.
- Butter – an essential ingredient for any cookie recipe. Room temperature butter is ideal for creaming together with the sugars.
- Eggs – large, room temperature eggs are ideal.
- Light brown sugar – you could also use dark brown sugar
- Granular sugar – also known as white sugar
- Vanilla extract – great for amplifying the flavor of the cookies.
- Oatmeal – quick oats or old-fashioned rolled oats (see the table below). Use oats labeled certified gluten-free if you need a gluten-free cookie. Don’t use steel-cut.
- Baking soda – a necessary leavening for baking cookies. Don’t leave this out!
- Salt – very helpful for flavor. You can reduce the amount, but don’t eliminate completely.
- Chocolate chips – I recommend semi-sweet, but mini chips, milk chocolate chips or chunks all work.
- Plain M&M candies – you could also use Mini M&M’s, Peanut M&M’s or Peanut Butter M&M’s.
For exact ingredient amounts and full recipe instructions be sure to scroll down to the bottom of the post for the recipe. Thanks!
Quick Oats vs. Old-Fashioned Oats
| QUICK OATS | OLD-FASHIONED OATS | |
| Texture | Softer, more uniform, tender | Heartier and chewier |
| Look | Smoother tops | Rustic, with oat flakes baked in |
| Best For | Soft, kid-friendly cookies | Classic bakery-style chew |
How to Make Monster Cookies
- Cream the butter and sugars. Your butter should be room temperature: not cold from the fridge and not nearly melted. Soft butter is what makes a fluffy, chewy cookie.
- Add the peanut butter, eggs and vanilla and mix until completely combined.
- Mix in the oats, baking soda and salt. The dough will be very thick. Fold in the M&M’s and chocolate chips.
- Chill (optional). For thicker cookies, refrigerate the dough for 1–2 hours.
- Scoop and bake. Use a ¼-cup measure or large scoop and place six cookies per baking sheet.
- Cool. Let cookies rest on the pan for 5 minutes, then move to a cooling rack.
Monster Cookie Size Guide
| Size | Scoop | Approx. yield | Bake at 350°F |
|---|---|---|---|
| Jumbo (this recipe) | ¼ cup | 24 | 12–14 min |
| Regular | 2 tablespoons | about 48 | 9–11 min |
| Mini | 1 tablespoon | about 90 | 7–9 min |
Tips for Thick, Chewy Monster Cookies
- Chill the dough. Refrigerating it for 1–2 hours firms up the butter, so the cookies spread less and stay thick and chewy in the middle.
- Don’t crowd the pan. Bake six jumbo cookies per sheet so air can circulate and they bake evenly.
- Use lined baking sheets. Silicone baking mats help cookies bake evenly and keep them from sticking.
- Pull them while the centers look soft. The edges should be golden; the centers will finish setting on the pan.
- Let them rest on the pan. Five minutes on the sheet keeps these big cookies from falling apart when you move them.
Monster Cookie Mix-Ins and Holiday Variations
- Mini chocolate chips or chocolate chunks
- Peanut butter chips or white chocolate chips
- Reese’s Pieces or mini Reese’s peanut butter cups
- Mini, peanut or peanut butter M&M’s
- Chopped peanuts
Make them for any holiday by swapping in seasonal M&M’s: red and green for Christmas cookie trays, orange and black for Halloween, pink and red for Valentine’s Day, pastels for Easter, and red, white and blue for the Fourth of July.
Want these as bars? Try my Monster Cookie Bars, made with the same ingredients and baked in a 15×10-inch pan.
Are Monster Cookies Gluten-Free?
This recipe has no flour, so it can be gluten-free. Oats are naturally gluten-free, but they’re often processed alongside wheat, so use oats labeled certified gluten-free. Check that your chocolate chips and candies are labeled gluten-free too.
How to Make Ahead and Freeze Monster Cookie Dough
| How | How long | Tips |
|---|---|---|
| Baked cookies, room temp | 3–4 days | Airtight container |
| Baked cookies, frozen | Up to 3 months | Freezer bag or airtight container |
| Dough, refrigerated | Up to 3 days | Covered tightly |
| Dough balls, frozen | Up to 3 months | Freeze on a tray, then bag. Bake from frozen, adding 2–3 minutes. |
Monster Cookie FAQ’s:
Monster cookies are made of butter, brown sugar, granulated sugar, eggs, peanut butter, vanilla, oatmeal, salt, baking soda, chocolate chips, and M and M candies.
Monster cookies get their name by their monstrous size. Most often, these cookies are double or triple the size of a regular cookie. These cookies are a mash-up of everyone’s favorite cookies; peanut butter, oatmeal, M and M and chocolate chip cookies.
Classic monster cookies, including this recipe, don’t use any flour. Oats and peanut butter give them structure. Some newer recipes add flour for a softer, cakier cookie.
To prevent your monster cookies from going flat you can do a couple things. First, use room temperature butter and eggs. When these are creamed together they will create a fluffy texture that will create small pockets of air, helping the cookies to remain fluffy when baked. Secondly, refrigerating the cookie dough before baking will help give you a thicker, chewy cookie.
The usual causes are natural peanut butter, packing the oats too firmly into the measuring cup, or overbaking. Use a no-stir peanut butter, spoon the oats in loosely, and pull the cookies while the centers still look soft.
One jumbo cookie from this recipe has about 340 calories. Make regular-size cookies with a 2-tablespoon scoop and you’ll get about half that per cookie.
Yes. Monster cookie dough can be frozen. You can freeze the dough in one large container, or roll out individual cookies and freeze. These can be baked as needed. Let dough thaw slightly before baking.
Yes. Almond butter works, and sunflower seed butter makes them nut-free. Heads up: sunflower seed butter can react with baking soda and turn the inside of the cookies slightly green. It’s harmless.
Cowboy cookies usually include flour, pecans and coconut. Monster cookies are built on peanut butter and oats and get their color from M&M’s.
More Cookie and Peanut Butter Recipes
- Monster Cookie Bars
- Penguin Cookies
- Cookie Dough Protein Balls
- Reese’s Pieces Cookies
- Peanut Butter Oatmeal Balls
- Reese’s Peanut Butter Cup Cookies
- Chocolate Peanut Butter Rice Krispie Treats
- Peanut Butter Protein Bars
- No Bake Granola Bars
- M&M Christmas Cookies
If you loved these monster cookies, check out our other irresistible cookie and bar recipes:
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Monster Cookies (Grandma’s Flourless Recipe)
Equipment
- Silicone Baking Mat Fits perfectly inside sheet pan, these baking mats help cookies bake evenly and slide out without sticking!
- Sheet Pan These USA Stainless steel sheet pans are great for everything from cookies to one-pan meals!
- Mixing Bowls These stainless steel mixing bowls are ideal for baking!
Ingredients
- 1½ cup, about 385 g creamy no-stir peanut butter
- 1 cup, 213g packed light brown sugar
- 1 cup, 200g granulated sugar
- ½ cup, 113/1stick butter room temperature
- 3 eggs room temperature
- 1 teaspoon vanilla extract
- 4½ cups (about 400g) quick or old-fashioned oats certified gluten-free, if needed
- 2 teaspoons baking soda
- ½ teaspoon salt
- 1⅓ cups, 227g semi-sweet chocolate chips
- 1⅓ cups, 275g plain M&M's plus extra for topping
Instructions
- Preheat oven to 350°F (175°C). Line baking sheets with silicone baking mats or parchment paper.
- In a large mixing bowl, cream together the butter and sugars until light and fluffy, about 2 minutes. Mix in the peanut butter, eggs and vanilla until completely combined.
- In a separate bowl, mix together the oats, baking soda and salt. Gradually add the oat mixture to the wet ingredients until fully incorporated. The dough will be very thick.
- Fold in the chocolate chips and M&M's
- Optional: for thicker cookies, cover and refrigerate the dough for 1–2 hours.
- Using a ¼-cup measuring cup or large scoop, form cookies on the baking sheet, six per pan. Press a few extra M&M's on top if you like.
- Bake for 12–14 minutes, until the edges are golden and the centers still look slightly soft.
- Let cookies cool on the pan for 5 minutes before transferring to a cooling rack to cool completely.
Notes
- Gluten-free: this recipe has no flour. Use certified gluten-free oats and check that your chocolate chips and candies are labeled gluten-free.
- Peanut butter: use a no-stir brand. Natural peanut butter makes dry, crumbly cookies.
- Smaller cookies: use a 2-tablespoon scoop and bake 9–11 minutes.
- Storage: keep cookies in an airtight container at room temperature for 3–4 days, or freeze for up to 3 months.
- Freezing dough: freeze scooped dough balls on a tray, then bag for up to 3 months. Bake from frozen, adding 2–3 minutes.
Nutrition
These sound yummy!! Thanks for sharing on Brag About it Tuesday! I’ll have to give these a try when I get a chance!
I am a BIG fan of the monster cookie, and these look terrific
I have had monster cookies in ages! My best friend used to always make them. Maybe I should make some and send them to her. 🙂
Lisa, this is such a great recipe – its from my grandma LaDene. Ya can’t go wrong with a grandma recipe! 🙂 Your friend will love it!!
Ooh, those are some good looking cookies, and just the right size as far as I’m concerned 😉
Mmmm- gotta love those!!!! YUM
wow, I’d love a couple of these right now! Thanks for joining us at Marvelous MOndays, pinned to my MM party board
I love chocolate and peanut butter too! Gotta love grandma recipes! Thank you for linking up to Saturday Night Fever!
I missed National Homemade Cookie Day, but that won’t stop me from making these cookies! I love oatmeal cookies, and then you added the chocolate and peanut butter flavors- heavenly! 🙂 Thank you for sharing your Grandma’s recipe with us!
Love, Joy
Yesterfood
Thanks so much, Joy!