October 25, 2022

Chocolate Monster Cookies

Monster cookies but make the cookie itself chocolate! These oat and peanut butter cookies use dutch cocoa to make a brownie-like cookie. You don’t need a mixer to make them and it’s a one bowl recipe. They’re packed with all the chocolate and candy you’d want in a monster cookie and by happy accident, are gluten-free. 

5 from 4 votes
Yield: 16 cookies
Jump to recipe


Recipe overview 


Huh, there I am again with the oat flour! 


I’ve wanted to do a chocolate twist on your typical monster cookie for awhile but the combination of rolled oats and cocoa proved pretty tricky. Luckily I was in full oat muffin mood and thought – well why not swap out the AP and the oats for oat flour? 


It surprised me once again with how amazing it is. Not only did these cookies have great flavor with the added oats (rather than the one dimensional ap flour) but the texture was just spot on; fudgy and soft while holding up structurally to all the added chocolate! 


Recipe Ingredients 

Butter: Unsalted, especially important here because we’re adding peanut butter which is already salted! No need to soften it but be careful when you melt it that you don’t lose any. 

Oat Flour: If you have done so successfully in the past, you can try making your own oat flour here. I use store-bought (Anthony’s or Arrowhead Mills). If you want to make these but don’t want to use oat flour, you can use all purpose – the cookie will be thicker and a little less fudgy but it still works. 

Cocoa: Dutch process – not black and not natural. This is important! 

Peanut Butter: Commercial creamy, one that doesn’t have any oil separation. I use JIF Natural. 

Candy & Chocolate: Chocolate covered candies, chocolate chips (or chunks) and peanut butter cups are both traditional and make for the perfect chunky cookie. 



Troubleshooting Chocolate Monster Cookies 


My cookies didn’t spread! 


Cookies don’t spread for one of the following reasons: the flour or cocoa measurement was too high or the butter too low (especially prone to happen when you don’t use a scale for the flour or when the butter sputters in the microwave and you lose some). 


My cookies spread too much! 


Similar to the above situation: they’ll spread if there is too much butter, the butter is too warm, or the flour/cocoa was under measured. 


In particular with this recipe: the cookies might spread more or less depending on the brand of peanut butter you use. Also, careful with that rest time, too little and they’ll spread too much, too long and they’ll get thicker. 

Making these Chocolate Monster Cookies ahead of time 


You can make this dough ahead of time but you’ll still want to give it time to rest at room temperature so here’s what I suggest: follow the directions below, fold in the candy and cover it so it sits at room temperature for half an hour. 


After half an hour, scoop the cookies onto a plate or small cookie sheet and flash freeze them: open and for 10 minutes. Once they are solid, you can place them in a ziplock bag and they won’t stick together. Keep the bag in the freezer until you want to bake them. 


Recipe for Chocolate Monster Cookies 

Chocolate Monster Cookies

Super chunky double chocolate monster cookies!
Prep Time: 10 minutes
Cook Time: 12 minutes
Chill Time: 30 minutes
Yields: 16 cookies
5 from 4 votes


  • 113g g or 1 stick unsalted butter
  • 210g or 1 cup granulated sugar
  • 50g or about 1/4 cup creamy peanut butter
  • ¼ tsp fine sea salt
  • 1 tsp pure vanilla extract
  • 1 large egg
  • ¼ tsp baking soda
  • ¼ tsp baking powder
  • 50g or 1/2 cup dutch process cocoa
  • 120g or 1 cup oat flour don't pack in the flour, and be sure to level the cup
  • 100 g chopped milk chocolate
  • Up to ½ cup candy covered chocolates
  • Peanut butter cups quartered or chopped


  • In a large bowl heat the butter in the microwave until melted (don’t let it over melt and sputter or you’ll lose some precious fat).
  • Add the sugar and whisk very well, for at least a minute.
  • Add the salt, vanilla and peanut butter and whisk well to combine.
  • Whisk in the egg.
  • Add the cocoa, baking soda, powder and oat flour and stir until the dough is mixed. Fold in the milk chocolate and candy chocolates. Leave the dough in the bowl, covered only with a tea towel for about 30 minutes.
  • Preheat the oven to 350 F. Line two greased cookie sheets with parchment paper.
  • Scoop the dough in 1.5 or 2 tablespoons onto the cookie sheet. Top with quartered peanut butter cups and more candied chocolates.
  • Bake for 10-12 minutes, until the cookies look dry on top and have set edges.

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Recipe Reviews

  1. 5 stars
    These cookies are so fudgy and delicious! I subbed out the peanut butter with a very smooth and spreadable almond and cashew butter. I found some almond butter cups at Trader Joe’s and subbed those in for the peanut butter cups. I used semi-sweet chocolate and Halloween M&Ms for the other mix-ins and added eye candies to the cookies after they baked. It turned out so well!

  2. 5 stars
    I made these with my daughter and they were wonderful! I baked the first pan too long b/c I thought they weren’t done–only do 12 mins at the most b/c they firm up when they cool. Followed the recipe except I used chopped candy bars (Snickers, KitKat, etc.) instead of chopped chocolate since that’s what I had. The perfect recipe to use up extra candy! I’ll definitely make this one again.

  3. 5 stars
    So delicious! I used 120g all-purpose flour and they did come out more brownie-ish rather than fudgy. They also spread less than I was expecting, but I just flattened out my scoops a bit and they were perfect. I put M&Ms and peanuts in my first batch – can’t wait to make more and experiment with mix-ins!