brownie monster cookies on cooling rack

Have you ever been at the crossroads of wanting a brownie and a Monster cookie at the same time, and you’re not sure what to do about it? Me too, friend, me too. That is why I present to you these brownie Monster cookies, which combine the soft, fudgy, chocolatey-ness of brownies with the classic flavors of Monster cookies — M&Ms, chocolate chips, oats and creamy peanut butter. No longer must we live in a world where we have to choose a brownie over a cookie or vice versa — with this easy and delicious brownie Monster cookie recipe, we can have both.

mixing ingredients in bowl

My initial inspiration for these cookies was, of course, Halloween, as the day is fast approaching and in need of a brownie cookie recipe (to offset all the candy, naturally). I think these cookies would be great for a Halloween party, or to munch on while handing out candy to trick or treaters or just to bake and eat around this time of year because you don’t need a serious reason to make these cookies anyway. You just need a hankering for brownies and Monster cookies at the same time (story of my life).

brownie monster cookie dough on baking sheet

brownie monster cookies

The batter for the cookies comes together with ease, combining flour, sugar, butter, cocoa powder and all the good mix-ins like creamy-smooth peanut butter, M&Ms, chocolate chips and oats. I wouldn’t recommend leaving any of them out as they not only contribute to the flavor and texture of the cookie, but they also help with their structure.

Once the batter comes together, it helps to refrigerate the dough for just a little bit so it’s easier to shape into cookies. The dough itself is pretty delicate, in order to keep the cookies soft and tender, so just a quick trip to the fridge will keep everything from turning into a chocolate-y mess ? add to file, “Situations I’ve Been In Before And Do Not Want To Repeat.” And since you want to only bake them until they’re JUST baked through, it’s good to give them a cool-down directly on the cookie sheet for a few extra minutes before transferring them to a cooling rack. Pro tips, y’all! Just helping you out in the name of brownies + cookies.

brownie monster cookie with bite taken

Other than that, my only advice to you is this: Let everyone else fight over the Halloween candy while you indulge in one or five of these brownie Monster cookies. We all know who the real winner is here.

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brownie monster cookies

Brownie Monster Cookies

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  • Author: Girl Versus Dough
  • Prep Time: 45 mins
  • Cook Time: 10 mins
  • Total Time: 55 mins
  • Yield: 24-26 cookies 1x
  • Category: Dessert
  • Method: Bake
  • Cuisine: American


  • 1/2 cup (1 stick) unsalted butter, softened
  • 3/4 cup packed brown sugar
  • 1/4 cup granulated sugar
  • 1 tsp vanilla extract
  • 1 egg
  • 1/2 cup peanut butter
  • 1/2 cup all-purpose flour
  • 1/2 cup cocoa powder
  • 1/2 teaspoon baking soda
  • 1 cup old-fashioned oats
  • 3/4 cup semisweet chocolate chips
  • 1/2 cup M&Ms candies, plus more for topping cookies


  1. Heat oven to 350 degrees F. In bowl of electric stand mixer or in large mixing bowl with electric hand mixer, cream butter and sugar on medium speed 3 minutes until pale and fluffy. Beat in vanilla, then egg. Beat in peanut butter until just combined.
  2. In separate large bowl, whisk or sift together flour, cocoa powder and baking soda. Add flour mixture to butter mixture and stir on low speed until just combined. Stir in oats, M&Ms and chocolate chips just until combined. Cover bowl with plastic wrap; refrigerate dough 30 minutes to make it easier to shape.
  3. Line a large cookie sheet with parchment paper. Scoop and roll dough into 24-26 balls; place 2 inches apart on cookie sheet. Flatten each ball slightly (dough won’t spread that much so this helps them bake into a classic cookie shape). Gently press a few more M&Ms into tops of cookies, if desired. Bake 10-12 minutes. Let cookies cool 5 minutes on cookie sheet before transferring to cooling rack to cool completely.