Stacked oatmeal cookie sandwiches

Cake Batter Monster Cookie Sandwiches

  • Author: Julianne Dell
  • Prep Time: 15 minutes
  • Cook Time: 14 minutes
  • Total Time: 29 minutes
  • Yield: 8 sandwiches - 16 cookies


Cake Batter Monster Cookies are chewy oatmeal cookies with vanilla cake mix and a layer of creamy vanilla frosting. The cookies are filled with MnMs, sprinkles and white chocolate chips.


  • 1/2 cup (113g) unsalted butter, cold
  • 1/2 cup (95g) granulated sugar
  • 1/2 cup (110g) light brown sugar
  • 1 large egg
  • 1 tablespoon (15ml) pure vanilla extract
  • 1 cup (140g) all purpose flour
  • 1/4 cup (35g) vanilla cake mix, dry
  • 1 cup (80g) rolled oats
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1/2 cup (90g) white chocolate chips
  • 1/2 cup MnMs
  • 1/4 cup sprinkles

For the frosting

  • 3/4 cup (170g) unsalted butter, cold
  • 2 1/2 cups (325g) powdered sugar
  • 2 teaspoons (10ml) pure vanilla extract
  • 1 tablespoon (15ml) milk or heavy cream
  • Additional Sprinkles for garnish


  1. Preheat the oven to 350° F. Soften the cold butter in the microwave for 10-15 seconds. Combine the softened butter with the brown and granulated sugar. Beat on medium speed until well combined, 2-3 minutes.
  2. Next add the egg and vanilla extract and continue beating until well incorporated.
  3. In a separate bowl, combine the dry ingredients: flour, cake mix, oats, salt and baking soda. Stir to combine and slowly add the dry ingredients into the dough, mixing on low speed until dough starts to form.
  4. Before the dough thickens, add the chocolate chips, MnMs and sprinkles. Beat a couple of times until they start to incorporate.
  5. Line a baking sheet with parchment paper or a silicone baking sheet. Scoop the dough using a large cookie scoop and place on a sheet pan, 2 inches apart.
  6. Bake for 13-15 minutes. The center of the cookie should be slightly under baked but not too gooey. Allow to cool on the baking sheet for 5-10 minutes before transferring to a wire rack to cool.
  7. For the frosting: Cut the butter into smaller pieces. Using the paddle attachment, whip the butter for 5-7 minutes, scraping down the bowl occasionally, beating until the butter is very fluffy.
  8. Add the powdered sugar, vanilla extract & heavy cream. Ensure the powdered sugar is well combined, then and whip for 3-4 minutes at high speed.
  9. To assemble the cookies, find two cookies that are similar in size. Use a piping bag or Ziploc bag and cut of the tip off the bag, swirl the frosting on one side of the cookie. Place a second cookie on top and gently press down. Then you can roll the edges in additional sprinkles.


  • Cake mix: Vanilla, yellow or white cake mix will work.
  • Oats: I prefer to use rolled oats but quick oats will also work
  • Storage: Keep these stored in an airtight container or Ziploc bag
  • When your cookies come out of the oven and they do spread or are misshaped, take a flat edge, such as a knife and press the edges of the cookie back towards the middle of the cookie, shaping it into a circle.
  • This recipe can easily be doubled. As written it makes 16 cookies (or 8 cookie sandwiches)
Nutrition Information:
1 Cookie Sandwich
  • Category: Cookies
  • Method: Baked
  • Cuisine: American