Cosmic Brownies

Name: Cosmic Brownies
Prep time: 15 min
Cook time: 25 min
Total time: 160 min
Ingredients: 2/3 cup Butter; 1 cup Granulated sugar; 1/3 cup Brown sugar; 3/4 cup Cocoa powder; 2 large Eggs; 1 Egg yolk; 1.5 tsp Vanilla extract; 2/3 cup All-purpose flour; 1 tbsp Cornstarch; 1/4 tsp Salt; 1/2 cup Cream; 1.5 cups Dark chocolate; Rainbow sprinkles

By Natasha MinochaPublished April 21, 2026 Jump to recipe Watch video

These fudgy, chewy homemade cosmic brownies are topped with a smooth, melt-in-your-mouth ganache and finished with colorful rainbow sprinkles. Rich, chocolatey, and easy to make, they are always a crowd favorite!

Brownie squares with chocolate frosting and rainbow sprinkles.

This copycat cosmic brownie recipe uses basic pantry ingredients to recreate the classic treat at home - full of nostalgia but without the preservatives. The result is soft, dense brownies with that signature chewy bite and a rich chocolate topping.

If you love brownies, then you must try my vegan brownie in a mug, chocolate raspberry brownie bites, or even my fudgy miso brownies !

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Why You'll Love This Recipe

✨ These homemade cosmic brownies have that soft, dense texture, with the perfect chewy bite - just like the classic.

✨ Made with simple pantry ingredients, this easy cosmic brownie recipe comes together quickly with no complicated steps.

✨ These brownies have all the nostalgic flavor you love, but richer, fresher, and without all the preservatives - so much better than the store-bought cosmic brownies.

✨ The smooth, glossy ganache with the rainbow sprinkles makes these brownies extra indulgent and special!

✨ These chocolate brownies are always a hit - great for lunchboxes, gatherings, or anytime the craving hits.

Recipe Ingredients

Labelled ingredients for making cosmic brownies.

Labelled ingredients for making chocolate frosting and rainbow sprinkles.

Butter: I prefer butter over oil here because it makes the brownies softer and much fudgier.

Sugar: Use both granulated sugar and brown sugar. The combo brings a balance of sweetness, moisture, and a deeper, caramel-like flavor.

Flour: All-purpose flour works the best.

Cornstarch helps make the brownies fudgier and chewier. Don’t skip it.

Eggs: Use 2 large eggs plus an extra yolk. The extra yolk is the secret weapon to richer, fudgier brownies.

Cocoa powder: These brownies are made with only cocoa powder. There is no melted chocolate here like in my easy gluten-free brownies. Feel free to use Dutch-process or natural cocoa powder.

Vanilla extract: For rounding out the flavors. Use good-quality store-bought or homemade vanilla extract.

Cream: I used 25% fat cream to make the ganache topping. You can use heavy cream if that's what is available to you.

Chocolate: I like to use 55% dark chocolate. Feel free to use semi-sweet chocolate.

Sprinkles: I couldn’t find the candy-coated chocolate sprinkles used in the OG Little Debbie cosmic brownies. So, I used regular rainbow sprinkles. You can use rainbow chips, mini-M&M’s, or any sprinkle you like.

Please see the recipe card below for full information about the ingredients and quantities.

How To Make Cosmic Brownies

Recipe Video

Step-By-Step Instructions

Melted butter, sugar, and cocoa powder in a mixing bowl.

Step 1: In a large microwave-safe bowl, melt the butter. Then mix in granulated sugar, brown sugar, and cocoa powder.

Eggs and vanilla extract on butter sugar cocoa powder mixture in a bowl.

Step 2: Allow the butter mixture to cool for a few minutes. Whisk in the eggs plus 1 egg yolk and vanilla extract. Mix very well.

Flour on top of chocolate mixture in a mixing bowl.

Step 3: Fold in the flour, cornstarch, and salt. Mix until just combined. This is a very thick batter.

Brownie batter in a parchment-lined square baking pan.

Step 4: Transfer the batter into the prepared pan and spread the batter evenly.

Baked brownie in a parchment-lined square pan.

Step 5: Bake the brownies for 22-25 minutes at 180 C / 350 F. Cool the brownies completely in the pan.

Cream and chocolate chips in a small mixing bowl.

Step 6: While the brownies are cooling, make the frosting. Heat the cream in a microwave or a saucepan (on low heat), until it just comes to a simmer. Add the chocolate and let sit for 1-2 minutes. Then mix well until smooth and shiny.

A hand spreading frosting on a brownie with a red palette knife.

Step 7: Spread the frosting evenly on the cooled brownie. Top the ganache with rainbow sprinkles.

Brownie in a parchment-lined square pan with chocolate frosting and rainbow sprinkles.

Step 8: Transfer the brownies to the refrigerator for 1 hour or until the frosting is set.

Squares of brownies with frosting and sprinkles on a parchment paper.

Step 9: Use a sharp knife to cut into 16 squares, then serve!

Top Tips

Use room temperature ingredients. This helps everything mix smoothly and evenly, giving you a better brownie batter and texture.
Use a kitchen scale to measure the ingredients. This will always give you accurate and better results when making brownies from scratch.
Allow the brownies to cool completely before frosting. This also helps in cleaner cuts.
Let the frosting set fully before slicing the brownies. I didn't wait long enough and ended up with cracks. The brownies still taste amazing though!
For the neatest cuts, use a sharp knife to cut the cosmic brownies. You can run your knife under hot water, wipe it dry, then make the cuts. It also helps to wipe the knife between each cut.
For the fudgiest brownies, don't overbake them. A skewer inserted in the center should come out with a few moist crumbs attached.

How To Store

I always prefer storing these copycat cosmic brownies in the refrigerator, as they are fudgier and chewier when chilled! They'll keep well for up to a week in an airtight container.

Recipe FAQs

What are cosmic brownies?

Cosmic brownies are a fun twist on classic chocolate brownies topped with chocolate ganache and colorful candy sprinkles, made famous by Little Debbie. They are known for their dense, chewy texture and nostalgic appeal.

Do these taste like Little Debbie cosmic brownies?

Yes, these cosmic brownies are inspired by the classic Little Debbie cosmic brownies, with the same chewy, fudgy texture and rich chocolate topping. Many find the homemade version even better - fresher and more chocolatey!

What sprinkles are used for cosmic brownies?

Classic cosmic brownies use small, colorful, candy-coated chocolate chips. These are available online. You can use mini M&Ms or rainbow sprinkles for the same look and crunch.

How do I make fudgy, chewy cosmic brownies at home?

For the best texture, don’t overmix the batter and don’t overbake the brownies. Chilling the brownies really helps, too. This recipe is designed to give you that soft, dense, chewy texture every time!