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!
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
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
Step 1: In a large microwave-safe bowl, melt the butter. Then mix in granulated sugar, brown sugar, and cocoa powder.
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.
Step 3: Fold in the flour, cornstarch, and salt. Mix until just combined. This is a very thick batter.
Step 4: Transfer the batter into the prepared pan and spread the batter evenly.
Step 5: Bake the brownies for 22-25 minutes at 180 C / 350 F. Cool the brownies completely in the pan.
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.
Step 7: Spread the frosting evenly on the cooled brownie. Top the ganache with rainbow sprinkles.
Step 8: Transfer the brownies to the refrigerator for 1 hour or until the frosting is set.
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
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.
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!
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.
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!
📖 Recipe
Cosmic Brownies
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
Frosting
- 1/2 cup Cream
- 1.5 cups Dark chocolate
- Rainbow sprinkles
Instructions
- Preheat the oven to 180 C / 350 F. Line an 8 x 8 -inch pan with parchment paper or grease it.
- In a large, microwave-safe bowl, melt the butter.2/3 cup Butter
- Stir in the granulated sugar, brown sugar, and cocoa powder.1 cup Granulated sugar, 1/3 cup Brown sugar, 3/4 cup Cocoa powder
- Let the mixture cool for a few minutes, then add the eggs, egg yolk, and vanilla extract. Mix well.2 large Eggs, 1 Egg yolk, 1.5 tsp Vanilla extract
- Add the flour, cornstarch, and salt and mix until well combined.This is a very thick batter.2/3 cup All-purpose flour, 1 tbsp Cornstarch, 1/4 tsp Salt
- Transfer to the prepared pan and bake at 180 C / 350 F for 22-25 minutes.Cool completely.You can also make them a day before and chill them overnight in the refrigerator.
Frosting
- In a small microwave-safe bowl, heat the cream for 1 minute. Add the chocolate chips and set aside for 1-2 minutes for the chocolate to melt.Mix well until the mixture is smooth and shiny.You can also heat the cream in a saucepan. On low heat, bring to a gentle simmer. Take off the heat immediately. Add the chocolate and let it stand for a few minutes for the chocolate to melt.1/2 cup Cream, 1.5 cups Dark chocolate
- Pour the frosting over the cooled brownies and spread evenly. Top with the rainbow sprinkles.Rainbow sprinkles
- Place in the refrigerator for 1 hour until the frosting is set.
- Use the parchment paper to lift the brownie out of the pan and slice it into 16 squares. Enjoy!
Video
Notes
- 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.
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