The Best Monster Cookies (Secretly Gluten-Free)

Baked Monster Cookies layered together on a dark wood background

Truly the best monster cookies! They are thick and chewy and bursting with oats and peanut butter with a healthy dose of chocolate. You will never guess they are gluten-free.


  • 2 1/4 cups (225gold-fashioned oats
  • 1/4 cup (24g) oat flour*
  • 1 1/8 teaspoons baking soda
  • 1/4 teaspoon salt
  • 5 Tablespoons (70g) unsalted butter, melted
  • 1/2 cup (100g) light brown sugar
  • 1/2 cup (100g) white granulated sugar
  • 2 large eggs
  • 1 cup plus 2.5 tablespoons (170g) creamy commercial-style peanut butter
  • 1/2 cup (4oz) chocolate candies, dark or milk chocolate*


  1. Combine the dry ingredients. In a large bowl, stir the oats, flour, baking soda, and salt together until combined.  
  2. Make the cookie dough. In the bowl of a stand mixer with a paddle attachment or a large bowl with a hand mixer, combine the melted butter, brown and white sugars, and beat on medium speed until smooth, about 2 minutes. Beat in the eggs, 1 at a time, until completely incorporated, about 2 minutes. Make sure there are no visible egg streaks in the batter. Add the peanut butter and mix until fully combined, about 3 minutes. Reduce the speed to low, and add 1/3 of the flour mixture at a time to the wet ingredients. Mix on low speed after each flour addition until combined. Stir in the chocolate candies. 
  3. Refrigerate. Cover the bowl tightly with plastic wrap and refrigerate for at least 4 hours. After 4 hours, you can bake all of the cookies or freeze some for later. See notes for freezing instructions.
  4. Bake. Adjust an oven rack to the middle of the oven. Preheat oven to 350°F (180°C). Line three half-sheet baking sheets with parchment paper. Scoop the cold dough in 2-tablespoon (45g) balls and arrange them 2-inches apart on the baking sheets. No need to roll the balls after scooping! Bake one baking sheet at a time until the edges are light golden brown, about 11-12 minutes.  Remove the baking sheet from the oven and transfer the baking sheet to a wire rack and let the cookies cool completely on the baking sheet. 



OAT FLOUR. If you opt to measure by volume instead of weight, whisk the flour first to aerate it, then spoon into a measuring cup, and then level it off with the back of a knife. If using whole wheat flour or all-purpose flour, only use 6 tablespoons (48g). 

CHOCOLATE CANDIES. If you choose to substitute some or all of the chocolate candies for chocolate chips, measure by weight instead of volume for the best results.

STORAGE. Store in an airtight container for 3 days at room temperature.

DO AHEAD. This cookie dough freezes wonderfully. Scoop the dough into 2-tablespoon balls, place them 1/2-inch apart on a sheet pan, and put the sheet pan in the freezer until the dough balls are frozen (about 2 hours). Once the dough balls are frozen, store them in a bag in the freezer until ready to bake. Bake them directly from the freezer and add 1-2 minutes to the total baking time. 


Keywords: monster cookies, gluten-free monster cookies, chewy monster cookies