These flourless Gluten Free Monster Cookies are packed with flavor from smooth peanut butter, tender oats, melty chocolate chips, and crunchy, candy-coated M&Ms.
Line the baking sheets with parchment paper or Silpat mats; set aside.
In the bowl of a stand mixer, cream the butter, peanut butter, and sugars until light and fluffy, about 2–3 minutes. Add the vanilla. With the mixing speed on low, add one egg at a time, mixing until incorporated.
In a medium-sized mixing bowl, combine the oats, baking soda, and salt. Whisk together. With the mixing speed on low, add the dry ingredients and mix until combined. Remove the bowl from the stand and fold in the M&Ms, chocolate chips, and peanut butter chips. Place the dough in the refrigerator to chill for 1 hour.
Remove the dough from the refrigerator and allow it to stand at room temperature for 10 minutes. Meanwhile, preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius). Scoop the cookies onto the prepared sheets using a standard-size cookie scoop; gently pat them down to slightly flatten. Place the cookie dough balls in the oven and bake for 10–12 minutes (they will look soft) before removing from the oven. Allow to cool on the sheets for 3 minutes before carefully transferring to a wire rack to cool completely.
Notes
*Make sure your oats are certified gluten-free. Bob’s Red Mill offers gluten-free oats, while Quaker Oats are not guaranteed to be safe for gluten-free baking.-Don’t skip the parchment or a mat—it’s key to helping these cookies bake evenly. Be gentle when transferring them to a rack; if they break slightly, press them back together and let them cool for an hour to firm up.STORE leftover cookies in an airtight container at room temperature for up to 4 days. To keep them soft, tuck in a slice of bread or a piece of parchment between layers. For longer storage, FREEZE baked cookies in a zip-top freezer bag for up to 2 months.When ready to enjoy, let them thaw at room temperature, or microwave for 10–15 seconds for a warm, chewy texture. These cookies also freeze well as dough—scoop, flatten slightly, then freeze on a tray before transferring to a bag. Bake from frozen at 350 degrees Fahrenheit (175 degrees Celsius), adding a minute or two as needed.