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cosmic brownie cookies on a sheet pan

Cosmic Brownie Mix Cookies

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These Cosmic Brownie Mix Cookies are topped with chocolate fudge frosting and rainbow crunch sprinkles. They are a copycat of the classic brownie treat and are so easy to make with only five ingredients!
Course Dessert
Cuisine American
Prep Time 10 mins
Cook Time 12 mins
Chill Time 30 mins
Total Time 52 mins
Servings 24
Calories 180


  • 18 oz box of brownie mix
  • 2 eggs
  • 1/4 cup butter melted
  • 1 cup chocolate fudge frosting
  • 5.25 oz container rainbow crunch sprinkles


  • Preheat oven to 350°F. Line a cookie sheet pan with parchment paper.
  • Stir together the brownie mix, eggs, and melted butter in a large mixing bowl until combined.
  • Scoop a heaping tablespoon worth of brownie dough onto the sheet pan (I like to use a cookie scoop for this), leaving about two inches between each cookie. Allow the dough to chill in the fridge for thirty minutes.
  • Bake for 11-12 minutes until the edges are set. Allow cookies to cool on the sheet pan for 5 minutes, then transfer to a cooling rack.
  • Microwave the frosting for 20 seconds, making sure to stir halfway through. You want the frosting to be thinned out but not soupy.
  • Spread about one tablespoon of the frosting on the top of each cookie and top with the sprinkles.


  • Where to find Rainbow Crunch Sprinkles: I found mine at the grocery store with all of the other sprinkles. You can also get them here.
  • Use the right brownie mix. Unfortunately, since all mixes are not made equally, some mixes will leave you with super-thin cookies. My favorite brownie mix is the kind in the picture above from Ghirardelli. If you can't find that one, choose a Pillsbury mix. I don't recommend mixes from Duncan Hines or Betty Crocker because they will spread too much. If you choose to use one of those, add 1/4 cup of flour to the mix.
  • Use the included syrup. If your brownie mix contains a packet of chocolate syrup, add it to the batter! It gives the cookies an even deeper chocolatey flavor.
  • Butter Substitute: You can substitute vegetable oil for the melted butter if you need to.
  • Don't overbake the cookies. They will get very tough if they overbake!
  • Line the sheet pan with parchment paper. This will help prevent the cookies from burning on the bottom and make clean up a breeze. 
  • Use a cookie scoop to help scoop out the dough. When you use a cookie scoop, all the cookies will be the same size, so they will cook evenly.
  • Don't skip the chill time for the dough. If you don't let the cookies chill, they will spread out too much, and your cookies will be too thin. 
  • Storing and Freezing: Store prepared cookies in an airtight container on the counter for up to 3 days. To freeze dough, simply place the chilled cookie dough balls into a freezer safe container and freeze for up to 3 months. Thaw the dough in the fridge before baking as directed. Freeze unfrosted/undecorated cookies in a freezer safe container or zipper freezer bag for up to 3 months. Thaw on the counter before enjoying.


Calories: 180kcal | Carbohydrates: 28g | Protein: 2g | Fat: 7g | Saturated Fat: 3g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Trans Fat: 1g | Cholesterol: 19mg | Sodium: 101mg | Potassium: 24mg | Fiber: 1g | Sugar: 22g | Vitamin A: 79IU | Calcium: 3mg | Iron: 1mg