If you love fresh-baked cookies but want the simplicity of a cake, this M&M Peanut Butter Cookie Cake is for you! With creamy peanut butter flavor and colorful M&M candies, it’s a fun, crowd-pleasing dessert perfect for any occasion.

If you’re looking for other desserts that involve cookies, take a look at our Birthday Sugar Cookie Cake, Easy Sugar Cookie Bars, and Cookies and Cream Poke Cake.

slice of peanut butter cookie cake on a plate
ingredients for giant peanut butter cookie cake

Kitchen Tip

After adding the cookie dough to the pan, use a piece of parchment or wax paper to press it down, keeping your hands clean and mess-free!

overhead shot of a slice of peanut butter cookie cake with M&M candies

Storage Suggestions

Store covered at room temperature for up to 3 days. FYI clean (never used) pizza boxes work great for storing a cookie cake.

Refrigerate/Leftovers

Cover the entire cake with plastic wrap or aluminum foil, or transfer it to an airtight container, and keep it fresh for up to 5 days in the fridge. Be sure to bring it back to room temp before eating.

Freeze

If you’d like to freeze your giant cookie, leave off the frosting and double wrap in plastic wrap and one layer of foil. Store in the freezer for up to 3 months. Thaw in the fridge, then decorate.

a slice of cookie cake

Recipe Notes + Tips

  • Avoid overbaking — ensure that the edges are a light golden brown and that the cake is still soft in the center.
  • Use room temperature ingredients. In a pinch, you can quickly bring the egg to room temperature by placing it in a glass of warm water for 10 minutes.
  • Skip natural peanut butter. Creamy regular peanut butter will work best to achieve the perfect chewy texture.
  • Use unsalted butter or omit the kosher salt. 
  • For a thinner cookie cake, use a 9×13 cake pan or 12-inch pizza pan and check for doneness after 12 minutes.
  • Slice the cake up into rectangles to make handheld, portable peanut butter cookie bars.
  • To make topping the cake easier, use a piping bag + tip to apply the frosting.
  • No piping bags? Just cut a corner off a disposable zip-top bag!
giant cookie pan for making cookie cakes

This pan is helpful for making cookie cakes! Also great for brownies and pizza.

Recipe Variations

Feel free to get creative! Here are a few fun ways to add your own twist to this cookie cake recipe!

  • Candy – Use seasonal M&M’s or use semisweet chocolate chips or chopped up peanut butter cups
  • Frosting – Use canned vanilla frosting or make Peanut Butter Frosting.
  • Topping – Drizzle with chocolate or caramel sauce.
  • Sprinkles – Skip the M&M candies on the top and use sprinkles instead.
giant peanut butter cookie cake photo collage
Peanut Butter Cookie Cake

Peanut Butter Cookie Cake

Yield: 8-12 servings
Prep Time: 10 minutes
Bake Time: 16 minutes
Total Time: 26 minutes

If you’re craving a fun and easy dessert, this Peanut Butter Cookie Cake with M&M candies is a winner. It’s quicker than making a batch of cookies and better than store-bought.

Ingredients

  • 1 ½ cups all-purpose flour
  • ½ teaspoon baking soda
  • ¼ teaspoon coarse kosher salt
  • ½ cup unsalted butter, softened
  • ¾ cup creamy peanut butter
  • ¾ cup light brown sugar, packed
  • ¼ cup white granulated sugar
  • 1 large egg, room temperature
  • 1 teaspoon vanilla extract
  • 1 cup M&M's, divided
  • ½ cup peanut butter chips

Instructions

  1. Preheat the oven to 350° F. and grease a 9-inch cake pan (or tart pan) with baking spray. Set aside. 
  2. In a medium bowl mix the flour, baking soda, and salt using a fork or wire whisk to combine. Set aside. 
  3. In a large mixing bowl add the butter, peanut butter, sugars, egg, and vanilla extract. Cream together with an electric mixer on medium speed until well combined (about 4 minutes). Use a spatula to scrape down the sides halfway through mixing.
  4. Add the dry ingredients to the wet ingredients. Mix on low speed for 10 seconds then increase speed to medium and mix just until combined. 
  5. Fold in  ½ cup of M&M’s and the peanut butter chips using a rubber spatula.
  6. Transfer the cookie dough to the pan. Use your hands to press the dough out evenly until flat. 
  7. Press ¼ cup of M&M’s into the top of the cake.
  8. Bake for 16-20 minutes or until the edges of the cookie are just starting to turn golden brown. Do not over bake, you want the cookie to be soft in the center. Remove cookie from oven and cool about 10 minutes on a wire rack, then run a knife around the edges of the pan to loosen cookie and invert onto rack to finish cooling completely before frosting. 
  9. Once cooled frost the cake to your liking. You can drizzle icing or use store-bought or homemade frosting to pipe onto the cookie cake. 
  10. Sprinkle the remainder of the M&M’s onto the frosting.

Notes

Store your cookie cake at room temp, covered, for up to 3 days (clean pizza boxes work great!).

For leftovers, wrap or store in an airtight container in the fridge for up to 5 days. Bring to room temp before serving.

To freeze, skip the frosting and double wrap in plastic and foil. Freeze for up to 2 months, then thaw and decorate.

Here’s a quick tip: After placing the cookie dough in the pan, press it down using parchment or wax paper to avoid a sticky mess on your hands!

Nutrition Information:
Yield: 12 Serving Size: 1
Amount Per Serving: Calories: 408Total Fat: 22gSaturated Fat: 10gTrans Fat: 0gUnsaturated Fat: 10gCholesterol: 38mgSodium: 194mgCarbohydrates: 47gFiber: 2gSugar: 30gProtein: 8g

Nutrition information is estimated based on the ingredients and cooking instructions as described in each recipe and is intended to be used for informational purposes only. Please note that nutrition details may vary based on methods of preparation, origin, and freshness of ingredients used and are just estimates. We encourage, especially if these numbers are important to you, to calculate these on your own for most accurate results.

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