These Mint Oreo Cookies are perfectly fudgy, soft, and filled with the best mint buttercream! This recipe is also crazy easy to make, requiring only 5 ingredients for the cookies!
In a large-size bowl using an electric handheld mixer on medium speed, beat together the softened butter and eggs until combined.
Sift the cocoa powder and cake mix together using a sieve into the wet ingredients and mix on low speed until the dry ingredients are well combined - the dough will be soft. Cover the dough and refrigerate for 30 minutes.
Preheat the oven to 350℉. Line 2 baking sheets with parchment paper. When done chilling, roll the dough into balls, using about 1 ½ tablespoons of dough per cookie. Place on the prepared pans leaving spreading room between each cookie.
Bake the pans of cookies in the preheated oven for 10-12 minutes or until the tops start to crack. Let cool on the pan for 5 minutes before transferring to a wire rack to finish cooling completely before sandwiching with the frosting. Bake the remaining cookies.
To make the Frosting:
In a medium bowl using an electric handheld mixer on medium speed, whip the softened butter until fluffy. Add the powdered sugar, peppermint extract, and vanilla and beat on low speed until well combined. Add milk if the texture is too thick. Add food coloring, 1 drop at a time, until your desired color is achieved. Pipe or spread with a knife, about 1 tablespoon of frosting per cookie, onto half of the cooled cookies. Sandwich together with the plain cookies. Enjoy!
Notes
Unsalted butter may be used instead, simply add ¼ teaspoon of salt for every ½ cup of butter.
This recipe was tested with a 375-gram box of Betty Crocker chocolate fudge cake mix.
You will need around 2 drops of artificial green food coloring and 1 drop of blue to make the minty green color. I used Watkins natural food coloring for the pictured cookies which is not as vibrant as artificial food coloring, so I used around 6 drops of green and 3 blue. Or you can omit the food coloring entirely.
Store cookies in an airtight container at room temperature or in the refrigerator for up to 3 days.