Monster Cookies

With peanut butter, chewy rolled oats, chocolate chips, butterscotch, and M&Ms, there’s something for everyone in these giant monster cookies!

I have been drooling over The King Arthur Flour Cookie Companion: The Essential Cookie Cookbook for ages. Deciding which recipe to make first was tough; I narrowed it down to a few, and finally decided on these monster cookies, which are surprisingly simple to make, considering the long list of ingredients. Everything goes in one bowl, which is especially handy with a stand mixer. Long story short, I think you’ll enjoy this recipe as much as I do!

Why Is It Called a Monster Cookie?

Well, these cookies happen to be monster-sized, so that might be one reason! Another theory is that they’re a little bit like Frankenstein’s monster, with a whole bunch of different elements added to the mix—like what would happen if you combined oatmeal cookies, chocolate chip cookies, M&M cookies, and peanut butter cookies.

What You’ll Need

Scroll down to the recipe card below this post for ingredient quantities and full instructions.

• Eggs – Let these come to room temperature for better incorporation into the dough, which helps give the cookies a softer texture. I recommend baking with large eggs.
• Brown sugar – Both light and dark brown sugar work, but dark brown sugar adds a deeper molasses flavor, making the cookies slightly richer.
• Granulated sugar
• Vanilla extract
• Corn syrup – Light corn syrup helps keep the cookies chewy and moist, balancing the crisp edges with a softer center.
• Baking soda
• Salt
• Unsalted butter – Melted butter makes these cookies soft and slightly dense. Be sure to let it cool slightly before adding, to avoid scrambling the eggs. Learn more by checking out unsalted or salted butter: which is better for baking?
• Chunky peanut butter – Chunky peanut butter adds texture with bits of peanuts, but creamy peanut butter works, too, if you prefer a smoother texture. Feel free to substitute with another nut or seed butter if needed for allergies.
• Rolled oats – Rolled oats (also called old-fashioned oats) add structure and chewiness to the cookies. Avoid quick oats, as they won’t give the same hearty texture. (See rolled oats vs quick oats for more information.)
• All-purpose flour – This post on how to measure flour is super helpful for this recipe, and all your baking needs.
• Semi-sweet chocolate chips – You can substitute chocolate chunks for a more rustic look and pockets of melted chocolate. Try combining semi-sweet and milk chocolate for added sweetness if desired.
• Butterscotch chips
• Mini or regular M&Ms – Use seasonal colors for a festive touch!

Monster Cookie Variations

The beauty of this recipe is that you can customize it with your own favorite mix-ins. Try different types of chocolate chips, toffee or caramel bits, chopped nuts, or anything else you like or happen to have on hand.

How to Make Monster Cookies

• Combine the first 8 ingredients. Stir together the eggs, sugars, vanilla, corn syrup, baking soda, and salt in a large mixing bowl. Once the mixture is well-combined, stir in the melted butter.

• Add the remaining ingredients. Next, mix in the peanut butter, oats, and flour. Fold in the chocolate chips, butterscotch chips, and M&Ms. The dough will be a bit loose.
• Chill the dough. Place the bowl of dough in the refrigerator and chill for about 30 minutes. The oats will absorb the butter and the dough will thicken.
• Prepare. Preheat your oven to 350°F and line baking sheets with silicone liners or parchment paper.

• Form the cookies. Drop the dough by 4-tablespoon portions onto the baking sheets. (I use a cookie scoop for this.) Flatten the top of each cookie slightly.
• Bake. Place one pan in the oven at a time and bake for 12 to 15 minutes, or until the cookies are lightly browned. Chill the remaining dough in the refrigerator between batches.
• Cool. Let the monster cookies cool on the pan on a wire rack for about 10 minutes, then carefully transfer them from the pan directly to a wire rack to finish cooling. (Learn more: Why every baker needs wire cooling racks.)

Proper Storage

• Room temperature: Store these monster cookies in an airtight container on the counter for 2 to 3 days. 
• Freezer: You can freeze monster cookies in an airtight, freezer-safe container or freezer bag for up to 3 months. Let the cookies thaw at room temperature or warm them up briefly in the microwave.
• Freezing the cookie dough: The dough can also be portioned and frozen for baking later; just add a few extra minutes to the baking time. Learn more: How to Freeze Cookie Dough

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