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A familiar favorite, but with a holiday twist! Grab the bag of Christmas colored M&Ms, your favorite holiday sprinkles, and make these Christmas Monster Cookies. They’re full of peanut butter, oats, chocolate chips, and candy–everything Santa loves!

Stack of Christmas monster cookies with red and green M&Ms and sprinkles on top.

These cookies really make the rounds in my house, because they span all 4 seasons. I make my plain small-batch Monster Cookies with seasonal colored candies and sprinkles anytime of the year. During Halloween, you have to pop on a few candy eye balls to give true monster vibes!

For these Christmas monster cookies, however, we’re using red and green chocolate candies and adorable holiday tree sprinkles.

This recipe makes 1 dozen large cookies, so everyone can have one before bed with a few leftover for Santa, too!

Ingredients

Small bowls of brown sugar, M&Ms, oats, and peanut butter.

Butter. Just a half stick of butter (4 tablespoons/ 57 grams), because we’re using peanut butter as a butter substitute here.
Peanut Butter. One-quarter cup of your favorite peanut butter. I recommend a no-stir peanut butter, because it blends better into the Christmas monster cookies batter.
Brown Sugar. One-half cup of brown sugar–it can be light or dark, whatever you have in your pantry. You might have some leftover from making my gingerbread crinkle cookies!
Egg. Yes, one whole egg, egg white and egg yolk. I know we normally split an egg for my small-batch cookie recipes, but this recipe is chunky and needs the whole egg.
Vanilla. Three-quarters of a teaspoon of vanilla extract for flavor.
Flour. One-half cup of flour doesn’t seem like enough for one dozen cookies, but the oats hold the dough together, too!
Rolled Oats. Make sure the package says ‘old fashioned rolled oats’ before measuring out 1/4 cup. Speaking of, you can definitely double this recipe if you want 2 dozen large cookies.
Baking Soda. One-half teaspoon of baking soda to help the cookies spread.
Salt. Never omit the salt in a baking recipe–it balances the sweetness. You need 1/4 teaspoon of fine sea salt for this recipe. You can also sprinkle large flakes of salt on top before serving.
Chocolate Chips. One-quarter cup of chocolate chips, any type you like: semisweet, dark, milk, or white chocolate are all amazing here.
M&Ms Candies. If you cannot find a bag of Christmas M&Ms, I can assure you that the 10-ounce bag of regular M&Ms contains exactly 1/4 cup of red and green candies. (I tested this recipe before the holiday candy was out, and I have separated the colors many times lol!)
Christmas Sprinkles. It’s optional, but 3 tablespoons of pretty Christmas sprinkles look really festive when serving!

How to Make Christmas Monster Cookies

Brown pottery bowl with half a stick of butter and a scoop of peanut butter.

Whipped yellow batter with a scoop of brown sugar on top.

Beat together the softened butter and peanut butter with an electric mixer until fluffy, about 1 minute.

Add the brown sugar, and beat to combine.

Whipped tan batter with a whole egg and splash of vanilla on top.

White bowl with flour, oats, chocolate chips, and red and green M&Ms.

Next, add the egg and vanilla; beat again to combine.

In a separate bowl, whisk all dry ingredients: flour, oats, baking soda, salt, chocolate chips, M&Ms and sprinkles.

Flour and oats with colorful sprinkles on top of tan whipped batter in bowl.

Twelve Christmas monster cookies on a sheet pan with extra sprinkles on top.

Add the dry ingredients to the wet, and stir with a spatula to combine.

Divide into 12 dough balls, sprinkling extra sprinkles and candy on top to make them super pretty. Bake for 10-12 minutes, let cool on pan for 5 minutes, then move to a wire rack.

Vertical image of colorful red and green Christmas monster cookies.

Make Ahead Tips:

This recipe may be doubled very easily to make 2 dozen cookies, if you need to, but please remember this cookies are quite large!
You can make the dough ahead of time, and refrigerate until needed. Let it soften on the counter for an hour first, scoop, and then let rest while the oven preheats. Then, bake as usual.
You can freeze these Christmas monster cookies in the dough ball phase. Let them thaw on the counter while the oven preheats, and bake as usual, adding another 1-2 minutes, if needed.
Already baking cookies may be frozen flat in between sheets of wax or parchment paper. Defrost at room temperature for 2-4 hours before serving.