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!

For more delicious easy dessert recipes, be sure to check out my Easy Banana Pudding, No Bake Blueberry Cream Pie, and Seven Layer Magic Bars to satisfy your sweet tooth!

chocolate cookies with icing and sprinkles

Oh how I love the classic cosmic brownie.

Those delicious little nostalgic snacks were one of my favorite childhood treats. 

a chocolate cookie with icing and rainbow sprinkles

My mom bought Little Debbie treats for us all the time growing up. Between cosmic brownies, oatmeal cream pies, and Christmas tree cakes, I’d have a hard time choosing just one favorite!

cosmic brownie mix cookies with sprinkles

If you’re a cosmic brownie lover like too, then you will love these brownie mix cookies! They are one of the easiest treats to make and sure to make everyone who tries them smile. 

Ingredients for Cosmic Brownie Mix Cookies

  • brownie mix
  • eggs
  • butter
  • chocolate frosting
  • rainbow crunch sprinkles

ingredients for cosmic brownie cookies

How to Make Cosmic Brownie Mix Cookies – Step by Step

Step 1: Preheat oven

Preheat oven to 350°F. Line a cookie sheet pan with parchment paper.

Step 2: Make the batter

Stir together the brownie mix, eggs, and melted butter in a large mixing bowl until combined.

cookie dough batter in a glass bowl

Step 3: Chill the dough

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. 

cookie dough balls on a sheet pan

Step 4: Bake

Bake for 11-12 minutes until the edges are set. Allow cosmic brownie mix cookies to cool on the sheet pan for 5 minutes, then transfer to a cooling rack.

chocolate cookies on a sheet pan

Step 5: Prepare frosting

Microwave the frosting for 20 seconds, making sure to stir halfway through. You want the frosting to be thinned out but not soupy. 

chocolate cookies on a sheet pan

Step 6: Decorate

Spread about one tablespoon of the frosting on the top of each cosmic brownie mix cookie and top with the sprinkles. 

Tips and Notes

  • Where to find Rainbow Crunch Sprinkles: I found mine at the grocery store with all of the other sprinkles. You can also get them from Michael’s, Walmart, or online here.
  • Use the right brownie mix. Unfortunately, since all mixes are not made equally, some mixes will leave you with super-thin cosmic brownie mix 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.

cosmic brownie mix cookies with sprinkles

 

  • 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. 

cosmic brownie mix cookies with sprinkles

  • 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. 

How to Store the Cookie Dough

If you don’t want to bake all the cosmic brownie mix cookies at once, you can place the chilled dough balls in an airtight container and store them in the fridge for up to one week. 

chocolate cookies with icing and sprinkles

How to Freeze Cosmic Brownie Mix Cookie Dough

I love to freeze cookie dough! That way I always have dough on hand when the mood strikes or when I need a quick dessert option. 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.

How to Freeze Cosmic Brownie Mix Cookies

Freeze unfrosted/undecorated cookies in a freezer safe container or zipper freezer bag for up to 3 months. Thaw on the counter before enjoying.

I don’t recommend freezing cookies with the frosting and sprinkles on top, as the frosting doesn’t hold together well when thawing. 

a chocolate cookie with icing and rainbow sprinkles

More Cookie Recipes You Might Enjoy!

cosmic brownie cookies on a sheet pan
5 from 2 ratings

Cosmic Brownie Mix Cookies

Yield: 24
Prep Time: 10 mins
Cook Time: 12 mins
Chill Time: 30 mins
Total Time: 52 mins
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!

Ingredients

  • 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

Instructions
 

  • 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.

Notes

  • 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.
Cuisine: American
Course: Dessert
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
Did you make this recipe?Let me know! Mention @TheBelleoftheKitchen on Instagram or tag #BelleoftheKitchen.