Easy Cosmic Brownie Cookies

4.46 from 11 votes

A boxed brownie mix is transformed into a delicious and easy Cosmic Brownie Cookie that will remind you of the ones you love from your childhood.

Prep Time10

Cook Time25

Total Time35

Course: Dessert

Cuisine: American

Servings: cookies

Calories: 422kcal

Preheat the oven to 350°. Combine the brownie mix and flour in a bowl and whisk until the ingredients are incorporated and any lumps are removed. In a separate bowl combine the eggs and oil, whisk until the ingredients are combined and add it to the dry ingredients. Using a wooden spoon {or hand held mixer}, stir the ingredients together until everything is well combined and thick. Use a ¼ measuring cup to measure cookie dough mounds. Form the dough into round discs. Bake 6 at a time for 11-13 minutes or until the edges are set, they will appear to be a little undercooked but that is alright. Remove cookies from the oven and let them cool on the cookie sheet.

Add the frosting ingredients to a large bowl and combine with an electric mixer {I used a hand held mixer} until the frosting is totally combined and smooth. Add additional heavy cream if the frosting is too thick.

Once the cookies are cooled {or almost completely} begin frosting the top of each cookie with a teaspoon of frosting and sprinkle with mini chips.
Store leftovers in an airtight container at room temperature for 3 days or the refrigerator for 4-5 days.

Don't over bake the cookies. Pull them from the oven once the sides are set and the middle is cooked but not completely done. If you bake the cookies too long, the brownie mix cookies will be dry instead of fudgy.
Allow the baked cookies to cool on the baking sheet. The residual heat from the baking sheet will continue to slightly bake the cookies and set them up perfectly.
Add the frosting to the cookies once they are slightly cooled but not all of the way. In order to get the glossy frosting that almost melts into the cookie, the cookie will need to be slightly warm.
Sprinkle with rainbow sprinkles while the frosting is still wet. If you wait too long the frosting will set up and the sprinkles will not stick.