Peanut Butter Oatmeal Monster Cookies

An overhead shot of a white plate with a pile of monster cookies and a wire rack of cookies on the side

Peanut Butter Oatmeal Monster Cookies

Enjoy chewy, delicious peanut butter oatmeal cookies packed with chocolate and M&Ms. This monster cookies recipe is the perfect sweet treat!

Course Cookies, Dessert

Cuisine American

Prep Time 10

Cook Time 15

Total Time 25

Servings cookies

Calories 141kcal

Author Liz Marino

Ingredients

½ cup creamy peanut butter use a no-stir variety
¾ cup unsalted butter at room temperature (1 and ½ sticks)
½ cup granulated white sugar
½ cup light brown sugar
1 large egg
½ tablespoon vanilla extract
¾ cups all-purpose flour
½ teaspoon baking soda
¼ teaspoon sea salt omit if using salted butter
1 cup old fashioned rolled oats
¾ cup M&Ms
¾ cup semi-sweet chocolate chips

Instructions

Preheat oven to 350°F, and line two baking sheets with parchment paper. Set aside.
On medium-high speed in a stand mixer fitted with the paddle attachment, or using an electric hand mixer and large mixing bowl, cream the peanut butter, butter, and both sugars together for 1-2 minutes, until light and fluffy.
Add the egg and vanilla extract; continue mixing on medium speed until well combined.
In a separate bowl, whisk together the flour, baking soda, and salt.
Reduce the mixer speed to low. Gradually add the dry ingredients to the wet mixture, mixing until just combined. *Avoid over mixing, which can cause cookies to be dry and crumbly.
Using a mixing spatula or spoon, gently fold in in the rolled oats, M&M's and chocolate chips, evenly distributing them throughout the dough.
Use a medium-sized cookie scoop or table spoon to portion the dough into 2-inch balls (about the size of a golf ball). Arrange them about 2 inches apart on the prepared baking sheets.
Press down lightly on each cookie dough ball to flatten them slightly.
Bake in preheated oven for 12-15 minutes, or until the edges are light golden brown and the centers are just barely set.
Remove from the oven and let the monster cookies cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.

Notes

For a softer texture, substitute half of the old fashioned rolled oats with quick-cooking oats.
To prevent cookies from spreading in the oven, consider refrigerating the dough for at least 30 minutes before baking. Chilling is optional, but it helps ensure thick and chewy cookies.
For even baking, make balls of cookie dough the same size. Either use a cookie scoop for portioning the dough, or weigh them on a food scale.

Storing: You can store the chewy monster cookies for up to 5 days in an airtight container at room temperature.

Freezing: You can freeze the baked cookies for up to 3 months in a freezer-safe container. Thaw completely before enjoying, or warm them up in a microwave for 10-20 seconds.

Freezing Unbaked Cookie Dough

You can freeze unbaked dough for up to 3 months. Before freezing, scoop and place balls of cookie dough on a parchment lined baking sheet, or use cookie dough freezing trays. Once the dough freezes, transfer the balls to an airtight, freezer-safe container.

When you're ready to bake:

Remove the cookie dough from the freezer.
Arrange unbaked cookies 2 inches apart on a baking sheet lined with parchment paper.
Thaw at room temperature for 30 minutes before baking.

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