Add 1 and ½ cups rolled oats to a blender. Blend on medium speed until a fine oat flour forms.
In a large mixing bowl, use a hand mixer to cream together the butter, light brown sugar, and white sugar on medium speed until smooth and creamy.
Add the peanut butter, eggs, and vanilla extract. Mix until smooth and cohesive.
Add 1 and ½ cups rolled oats, the oat flour, and baking soda. Mix until just combined.
Fold in the M&Ms, white chocolate pretzels, peppermint bark, and sprinkles. Reserve a handful of add-ins to press into the tops of each cookie dough ball.
To make 12 cookies, use a 2-ounce cookie scoop to measure out 6 cookies on the baking sheet. Leave at least 2 inches between each cookie. Press a few add-ins to the top of each cookie dough ball. Bake at 350F on the middle oven rack for 11-13 minutes, until golden around the edges. The center will still look soft but not raw.
To make 24 cookies, measure out twelve 2 tablespoon-sized cookies. Leave at least 2 inches between each cookie. Press a few add-ins to the tops of the cookie dough balls. Bake at 350F on the middle oven rack for 9-11 minutes, until golden around the edges. The center will still look soft but not raw.
Let cookies cool at least 10 minutes before enjoying.
Peanut butter: I tested this recipe with Jif natural peanut butter and Jif regular peanut butter.
Gluten-free options: The cookie dough is gluten-free if you use gluten-free rolled oats and gluten-free pretzels. Check labels to ensure the M&Ms, sprinkles, and peppermint bark are gluten-free. Regular gluten-free pretzels can be used if unable to find GF chocolate-coated pretzels.
Storage: Keep at room temperature in an airtight container for up to 4 days.
To freeze the baked cookies, let cool to room temperature before transferring to an airtight container. Freeze for up to 3 months. They will thaw quickly at room temp, or you can pop in the microwave for 20-30 seconds to warm.
To freeze the cookie dough, you can either freeze the entire batch or freeze individual balls. Let the cookie dough thaw overnight in the fridge before using. Individual cookie dough balls can be baked immediately, just add an extra minute to the bake time.
Nutrition: Add-ins are not included in nutrition facts. Nutrition facts are an estimation and will vary based on brands used.