These soft and chewy monster cookies are packed with hearty oats, creamy peanut butter, colorful M&M’s, and melty chocolate chips. Every bite is filled with the classic flavors that make monster cookies so nostalgic and comforting, bringing back memories of homemade treats enjoyed with family and friends.
This easy monster cookie recipe is a true family favorite and always a crowd-pleaser. The small batch yields 12 cookies and requires just a quick 30-minute chill time, making it perfect for when you want a fun, satisfying cookie without spending hours in the kitchen.
Ingredients
- 5 tablespoons unsalted butter
- 1/3 cup light brown sugar
- 2 tablespoons granulated sugar
- 1/2 teaspoon vanilla extract
- 1 large egg yolk
- 1 tablespoon creamy peanut butter
- 1/4 teaspoon salt
- 1/2 teaspoon baking soda
- 1/2 cup + 1 tablespoon all-purpose flour
- 1/4 cup old-fashioned oats
- 2 tablespoons mini semi-sweet chocolate chips
- 2 tablespoons mini M&M’s
Step by step instructions
Note: Find the full ingredient measurements and instructions in the recipe card at the bottom of this page.
- Microwave butter in heatproof bowl for 30 seconds on high until melted. Set aside to cool for a couple minutes. Add brown sugar and granulated sugar and mix until combined.
- Add egg yolk, vanilla extract, and peanut butter. Mix until combined.
- Add salt, baking soda, flour, and oats. Mix until just combined. Mix in chocolate chips and M&M’s. Be careful not to over mix.
- Line a baking sheet with parchment paper. Scoop out 12 cookies. Add 3-4 M&M’s on top of each cookie dough. Refrigerate dough for 30 minutes.
- Preheat oven to 350° F. Bake for 11-12 minutes.
Why you’ll love these monster cookies
- Small Batch Recipe – Makes just the right amount of cookies, perfect for a sweet treat without baking a full batch.
- Classic Monster Cookie Flavor – Packed with oats, creamy peanut butter, M&M’s, and chocolate chips for that nostalgic, bakery-style taste.
- Soft & Chewy Texture – The perfect balance of tender centers and slightly crisp edges in every bite.
- Great Make-Ahead Cookie Dough – Chill or freeze the dough ahead of time so fresh monster cookies are always ready to bake.
- Easy, No-Fuss Recipe – Simple ingredients and straightforward steps make these cookies beginner-friendly and dependable every time.
Frequently asked questions
If your cookies didn’t spread, you probably added too much flour. If you don’t have a kitchen scale, you can use the scoop and level method. Even an extra tablespoon of flour will make a huge difference!
Chilling the dough for 30 minutes allows the fats to solidify and the dough to dry out resulting in a higher concentration of sugars. The cookie will not spread as much and will be chewy and delicious.
If your cookies aren’t soft, chances are you over baked them. Even an extra minute will make a big difference. When you pull them out, the center will look soft, but they will set as they cool on the baking sheet.
My favorite is a 1.5 tablespoon cookie scoop. I like this one here.
As soon as you remove the cookies from the oven, use a cookie/biscuit cutter and gently scoot them into a circle. Be careful not to scoot too hard or they may smoosh together. You could also use a small bowl that’s slightly larger than the cookies too!
White chocolate chips, butterscotch chips, raisins, or nuts. Be sure to limit the mix-ins to a max of 2 different types and a combined total of a 1/4 cup. Anything over will crowd the dough.
Tips for the best monster cookies
- Use Creamy Peanut Butter – Stick with regular creamy peanut butter (not natural) for the best texture and consistent results.
- Do Not Overbake – Monster cookies should look slightly underbaked in the centers; they’ll continue to set as they cool, keeping them soft and chewy.
- Chill the Dough – A short chill helps prevent spreading.
- Customize the Mix-Ins – Swap in peanut butter chips, chopped Reese’s, or mini M&M’s while keeping the total mix-in amount the same.
- Use a Cookie Scoop – This ensures evenly sized monster cookies that bake at the same rate.
- Cool on the Pan First – Let cookies cool for a few minutes before transferring to a rack to help them set without falling apart.
Storing and freezing instructions
These cookies are best fresh, but can be kept in an air tight container up to 3 days.
To freeze the cookie dough, roll the dough into balls and place them on a plate and set in the refrigerator for 15 minutes. Then transfer them to a freezer safe ziploc bag and freeze for up to 3 months. Remember to label the dough with what it is, the date you made the batch, and the baking time as well. Add an additional 1-2 minutes onto the baking time when baking frozen dough.
Did you make this?
Please rate the recipe and leave a comment below. This helps other readers decide if this is a great recipe to bake. Be sure to tag me on Instagram using @schmidtybakes so I can see. I love to see what you’re baking!
Monster Cookies
Ingredients
- 5 tablespoons (71g) unsalted butter
- 1/3 cup (73g) light brown sugar
- 2 tablespoons (25g) granulated sugar
- 1/2 teaspoon vanilla extract
- 1 large egg yolk (room temperature)
- 1 tablespoon (16g) creamy peanut butter
- 1/4 teaspoon salt
- 1/2 teaspoon baking soda
- 1/2 cup + 1 tablespoon (72g) all-purpose flour
- 1/4 cup (20g) old-fashioned oats
- 2 tablespoons (20g) mini semi-sweet chocolate chips
- 2 tablespoons (20g) mini M&M's (plus more for topping)
Instructions
- Microwave butter in heatproof bowl for 30 seconds on high until full melted. Allow to cool for a few minutes. Add brown sugar and granulated sugar and mix until combined.
- Add vanilla extract, egg yolk, and peanut butter and mix until combined.
- Add salt, baking soda, flour, and oats and mix until just combined. There should still be some streaks of flour visible. Stir in chocolate chips and M&M’s.
- Line a baking sheet with parchment paper. Scoop out 12 cookies using a #40 (1.5 tablespoon) cookie scoop. Add 3-4 M&M’s on top of each cookie dough. Gently press them into the dough so they don’t fall of when transferring them. Refrigerate dough for 30 minutes.
- Preheat oven to 350° F. Bake for 11-12 minutes. Allow to cool slightly before serving.
Notes
The nutrition facts provided are calculated using a third-party tool and are estimates only. Actual nutritional content may vary based on the ingredients and brands you use, as well as portion sizes. For accurate results, please consult a registered dietitian or nutritionist.
Incredible. Maybe my new favorites.