Cosmic Brownie Cookies (Brownie Mix Cookies)

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If you love Cosmic Brownies, you’re going to go crazy for my Brownie Mix Cookies!! Made with brownie mix and topped with homemade chocolate frosting and colorful sprinkles, cosmic brownie cookies are delicious and totally easy to make! Using boxed brownie mix will save you so much time and effort without giving up any flavor!

Titled Image: Cosmic Brownie Cookies Brownie Mix Cookies


Brownie Mix Cookies

Longtime readers of the blog know just how much I love cookies. They’re my go-to for an easy dessert and I like having them on hand for Chad and Munchkin. 

I also always have some sort of cookie swap/bake sale/get-together on the calendar.

I’m kind of obsessed with having an arsenal of recipes on hand so I never run out of ideas!

And so this brownie mix cookies recipe was born. I don’t know about you guys, but I have always loved Cosmic Brownies from the supermarket.

I got the bright idea to turn them into cookies… and I think I found yet another obsession!! 

This cosmic brownie cookies recipe starts with brownie mix, which means it’s incredibly easy to make.

Chewy and fudgy cookies are decorated with homemade frosting and those sprinkles you all know and love!

Don’t miss my recipes for Raspberry Cookies, these triple chocolate beauties, and these uniquely sweet and chewy Butterscotch Oatmeal Cookies too!

ingredients for cosmic brownie cookies

Ingredient Notes and Substitutions

  • Brownie Mix – I love Pillsbury brownie mix myself, but you can use your preferred brand.
  • Cocoa Powder – I dress up the brownie mix with a few yummy extras, including cocoa powder. The results?

    A rich, fudgy, and oh-so-chocolatey batter that you’ll want to eat straight from the mixing bowl.
  • Powdered Sugar – For that homemade frosting! I prefer powdered over granulated sugar as it mixes up a lot better. 
  • Chocolate Syrup – Use a bottle from the store or my homemade version — up to you! 
  • Vanilla – You’ll need it for the cookie batter and for the chocolate frosting.
  • Multi-Colored Sprinkles – A Cosmic Brownie cookies recipe would not be complete without rainbow sprinkles!

    You can use the same kind you add to ice cream, or opt for the rainbow chip sprinkles that are found on original Cosmic Brownies.

Tips for Making Cosmic Brownie Cookies

mixing cosmic brownie cookie batter
  • Use the right tools.

You may be tempted to use a large spoon to portion out your Cosmic Brownie cookies, but I can’t say enough good things about using a cookie scoop!

It’s the ultimate hack for evenly sized chocolate frosted cookies. 

  • Don’t overmix!

Baking is a science, so you need to make sure to complete every step with care. 

Overmixing will result in a very dense and possibly dry treat. Make sure that everything is combined, but don’t overdo it.

  • Be patient.

I know you’ll be tempted to frost these brownie mix cookies as soon as they come out of the oven. But, you need to wait for about 10 minutes before you do.

Pull your cookies out of the oven when the edges are set but the center is still soft.

Leaving them on the baking sheet ensures that they finish baking without becoming hard!

scooped cookie dough

Storing Chocolate Frosted Cookies

Once your treats are completely cool, you can store them in an airtight container on the countertop or in the fridge. They will keep for up to 1 week.

I suggest adding a piece of parchment paper in between each layer of cookies to keep the frosting and sprinkles relatively intact. 

mixing frosting for cosmic brownie cookies

Kitchen Tools You Will Need

  • Baking Sheets lined with parchment paper – Used for anything from cookies to roasting, a good baking pan will last for years.
  • Mixing Bowls – I like to have a variety of sizes on hand, and this set has them all.
  • Electric Hand Mixer – I’ve had this one in my kitchen forever and it still works beautifully.
  • Cookie Scoops – Great for meatballs, cookies, ice cream, and portioning out leftovers. I’ve had this set for years and use them all the time.
pouring frosting on top of cosmic brownie cookies

Cosmic Brownie Cookies Recipe FAQ

What’s the difference between Cosmic Brownies and regular brownies?

Cosmic Brownies typically refer to Little Debbie Cosmic Brownies. They’re known for their colorful candy-coated sprinkles over a layer of frosting, and I’m willing to bet you’ve eaten one at some point in your life!

Regular brownies don’t usually feature frosting or sprinkles and can be store-bought or homemade. 

Can I use different colored sprinkles for chocolate frosted cookies?

Absolutely! I love the idea of making this cosmic brownies cookie recipe holiday-themed. Use red and white for Christmas, or red white and blue for the Fourth of July. 

Or, make them for a special someone’s birthday and use their favorite colors. There are so many possibilities!

How do I make brownie mix cookies fudgy?

The key is to take them out of the oven as soon as the edges get crispy. Remember that your cosmic brownie cookies will continue to bake as they sit on the baking sheets. 

Undercooking them ever so slightly will pretty much guarantee fudgy results!

cosmic brownie cookie closeup

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cosmic brownie cookies sliced in half

cosmic brownie cookies closeup

Cosmic Brownie Cookies (Brownie Mix Cookies)

Donna Elick
These Brownie Mix Cookies are Cosmic Brownies in cookie form! Chocolatey and chewy, this cosmic brownie cookies recipe is fun AND tasty!
5 stars from 2 reviews
Tried this recipe?Please comment and review!
Prep Time 10 minutes
Cook Time 8 minutes
Total Time 18 minutes
Course Dessert
Cuisine American
Method Oven
Servings 14 -16 cookies


Cookie Ingredients:

  • 1 box of dark chocolate brownie mix, I used Pillsbury 18.4 ounce box
  • 2 tablespoons cocoa powder
  • 2 eggs
  • 1/4 cup unsalted butter, melted
  • 1 tablespoon chocolate syrup
  • 1 teaspoon pure vanilla extract

Frosting Ingredients:

  • 2 cups powdered sugar
  • 1/2 cup cocoa powder
  • 1/4 cup water + extra if needed
  • 2 teaspoons pure vanilla extract
  • 1/3 cup multi colored sprinkles


  • Line two baking sheets with parchment paper and preheat the oven to 375 degrees.
  • In a medium or large bowl, combine the brownie mix and cocoa powder.
  • Stir in the eggs, melted butter, chocolate syrup, and vanilla extract until mixed well – but don’t over mix.
  • Use a two tablespoon cookie scoop and create heaping cookie dough balls and place them at least 2” apart on the baking sheet – do NOT press down or flatten.
  • Bake for 8 minutes or until the edges are set. The center may still be a little soft.
  • Remove from the oven and let cool for at least 10 minutes on the baking sheet.
  • While one batch cools, bake the other 1-2 batches depending on the size of the baking sheet.
  • After the cookies are cooled, whisk together the frosting by combining the powdered sugar and cocoa powder.
  • Add the water and mix well.
  • Stir in the vanilla until smooth.
  • Spoon the frosting on top of each cookie and then sprinkle with the multi-colored sprinkles.
  • Let the frosting cool completely before storing.

Donna’s Notes

I like to use a heaping 2 tablespoon scoop of cookie dough which will yield about 14 cookies. If your cookie dough balls are exactly 2 tablespoons the recipe will yield about 16 cookies.
The cookies can be made a day or two before and then add the frosting when you’re ready to serve.
Store the cookies in an airtight container at room temperature for up to 1 week or in the refrigerator.
Cookie dough balls can be frozen for up to 3 months before baking and adding the frosting.


Serving: 1 | Calories: 136cal | Carbohydrates: 24g | Protein: 2g | Fat: 5g | Saturated Fat: 3g | Cholesterol: 32mg | Sodium: 12mg | Sugar: 21g | Fiber: 1g | Calcium: 10mg | Iron: 1mg

All nutritional information is based on third party calculations and is only an estimate. Each recipe’s nutritional value will vary depending on the ingredients used, measuring methods, and portion sizes.

Tried this recipe?Let us know how it was!
Cosmic Brownie Cookies (Brownie Mix Cookies) - PIN

Originally published October 2023

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  1. 5 stars
    I had the kids help with these cookies last night and they loved making them. Easy to follow recipe and the most delicious cookies ever!

  2. I’m making these cookies with my grandson this afternoon but need to know if 1/2 cup of cocoa in the frosting is the correct measurement. It seems like a lot to me and I don’t want to ruin my cookies with too much cocoa.
    Please HELP!

    1. Hi Anita,
      The measurement is correct and the frosting is delicious! You can use 1/4 of a cup and taste it to see if you like it with less, hope this helps you! Enjoy!
      TSRI Team Member,

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