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Cosmic Brownies are the fudgy, candy topped chocolate squares my girls beg for, and this homemade version tastes even better than the lunchbox classic. I first made a batch on a rainy Saturday afternoon when Maddie and Lizzie wanted something chocolatey and colorful, and the rainbow chips disappeared before the ganache even set. If you love an easy chocolate treat, you will want these right next to our chocolate brownies with strawberry frosting.
With one bowl, a handful of pantry staples, and a glossy chocolate ganache on top, these cosmic brownies come together fast and slice into perfect candy covered squares every single time.
Cosmic Brownies Quick Look
- 🕒 Prep Time: 10 minutes
- 🌡️ Cook Time: 25 minutes
- ⏳ Total Time: 3 hours 35 minutes
- 🍽️ Serving: 9 brownies
- ⚡ Calories: 439kcal
- 🌶️ Flavor Profile: Rich, fudgy chocolate with a sweet candy crunch
- ✋ Difficulty: Easy, on par with our Mississippi mud brownie bars
Quick Answer
Beat melted butter, sugar, cocoa, eggs, vanilla, milk, and corn syrup until smooth, fold in flour and salt, then bake in an 8×8 pan at 350 degrees for 20 to 25 minutes. Cool completely, top with a milk and semi sweet chocolate ganache, scatter on rainbow chip sprinkles, and chill until set.
Jump to:
Why This Recipe Works
Click to see the technique science
- Cocoa plus a chocolate ganache. Cocoa powder in the batter gives a deep, fudgy crumb while the milk and semi sweet ganache on top delivers that signature glossy chocolate shell.
- Corn syrup keeps it chewy. A spoonful of light corn syrup traps moisture so the brownies stay dense and chewy for days instead of drying out.
- Beating the wet ingredients first. Whipping the butter, sugar, eggs, and cocoa together before the flour goes in dissolves the sugar and builds that shiny, crackly top.
- Folding the flour by hand. Stirring in the flour gently, just until combined, keeps the gluten low so the texture stays soft and fudgy, never cakey.
- Chilling sets the ganache. A few hours in the fridge firms the ganache into a sliceable layer so every square cuts clean with that candy topped finish.
Why You’ll Love This Recipe
- They taste just like the Little Debbie cosmic brownies you grew up on, only richer, fudgier, and made fresh in your own kitchen.
- One bowl and a hand mixer get the batter done, so there is barely any cleanup and the kids can help measure and stir.
- If you love a chewy chocolate treat, these sit right alongside our cosmic brownie cookies for a fun bake sale or lunchbox pairing.
Key Ingredients
Here is what makes these cosmic brownies so rich and fudgy. See the recipe card below for the exact amounts.
- Cocoa powder: Use a good unsweetened cocoa for the deepest chocolate flavor in the brownie base.
- Butter and corn syrup: Melted butter plus a little light corn syrup is the combo that keeps these dense, chewy, and shiny on top.
- Eggs and sugar: Beaten together they build structure and that crackly top everyone fights over.
- Chocolate for the ganache: Milk chocolate chips plus a chopped semi sweet bar melt into a smooth shell, just like the one on our German chocolate brownies.
- Rainbow chip sprinkles: The candy coated chips on top are what make them officially cosmic. Look for them in the sprinkle aisle.
See recipe card for exact quantities.
Variations and Substitutions
Here are a few easy ways to make these cosmic brownies your own.
- Swap the rainbow chips for crushed candy or mini chocolate chips if you cannot find the cosmic style sprinkles.
- Stir a handful of chocolate chips into the batter for an extra fudgy, double chocolate bite like our double chocolate muffins.
- Add a teaspoon of espresso powder to the batter to deepen the chocolate flavor without making them taste like coffee.
- Drizzle the cut squares with warm homemade hot fudge sauce for an over the top dessert.
How to Make Cosmic Brownies
- Preheat your oven to 350 degrees. Spray an 8×8 baking dish with nonstick spray and line it with parchment paper. In a large bowl, beat the melted butter, sugar, cocoa powder, vanilla, eggs, milk, and corn syrup with a hand mixer until smooth and glossy.
- Fold in the flour and salt just until combined, with no dry patches left. Pour the batter into the prepared pan and smooth the top into an even layer.
- Bake for 20 to 25 minutes, until a toothpick inserted in the center comes out clean. Set the pan on a wire rack and let the brownies cool completely.
- Make the ganache. Warm the heavy cream in a small saucepan just until it simmers, then remove from the heat and stir in the milk chocolate chips and chopped semi sweet chocolate until melted and smooth.
- Pour the ganache over the cooled brownies and spread it into a smooth, even layer all the way to the edges.
- Scatter the rainbow chip sprinkles over the top, then chill for about 3 hours so the ganache sets before slicing into squares.
Recipe Tips & Tricks
- Line the pan with parchment so you can lift the whole slab out and cut clean squares on a cutting board.
- Do not overbake. Pull them at 20 to 25 minutes when a toothpick comes out with a few moist crumbs, not wet batter.
- Let the brownies cool completely before adding the ganache, or it will slide right off the warm top.
- Simmer the cream, never boil it. Boiling can make the ganache grainy, so pull it off the heat the moment you see bubbles at the edge.
- Add the sprinkles while the ganache is still wet so they stick, then chill to set them in place.
- Store leftovers in an airtight container for up to 5 days, the same way we keep our butterfinger brownies fresh.
Serving Ideas and Suggestions
These cosmic brownies are made for sharing. Cut them into small squares and pile them on a platter for a birthday party, bake sale, or after school treat. The candy topping makes them a guaranteed hit with kids and grown ups alike.
For a full dessert spread, serve them next to our Reese’s stuffed peanut butter brownies and a batch of Bailey’s brownies so there is a chocolate treat for everyone. A cold glass of milk is all you really need on the side.
Want to turn one into a sundae? Warm a square for a few seconds, add a scoop of vanilla ice cream, and spoon over our cookies and cream hot fudge sauce.
Cosmic Brownies FAQs
Cosmic Brownies are a fudgy chocolate brownie topped with a smooth chocolate ganache and rainbow candy coated chips. This homemade version tastes just like the classic Little Debbie snack, only fresher and richer.
The rainbow chip crunch sprinkles are sold in the baking and sprinkle aisle of most grocery stores and online. If you cannot find them, crushed candy coated chocolate or mini chips work just as well.
Keep Cosmic Brownies in an airtight container in the refrigerator for up to 5 days. The chilled ganache stays set and sliceable. Let them sit at room temperature for a few minutes before serving.
Yes. Freeze the cut squares in a single layer, then transfer them to an airtight container for up to 3 months. Thaw in the fridge overnight before serving.
Cakey brownies usually mean too much flour or too long in the oven. Spoon and level your flour, fold it in gently, and pull the pan as soon as a toothpick comes out with moist crumbs.
Absolutely. Bake and top the brownies up to 2 days ahead, store them covered in the fridge, and slice just before serving for clean candy topped squares.
Ready for more easy chocolate desserts? Try our thick and chewy butterfinger brownies next, then come back and tell us how your cosmic brownies turned out.
Cosmic Brownies
Ingredients
Brownies:
- ½ cup melted unsalted butter
- 1 cup granulated sugar
- ¾ cup cocoa powder
- 2 teaspoons vanilla extract
- 2 eggs lightly beaten
- 2 Tablespoons milk
- 1 Tablespoon light corn syrup
- ¾ cup all-purpose flour
- ¼ teaspoon salt
Ganache:
- ½ cup heavy cream
- ½ cup milk chocolate chips
- 4 ounce semi-sweet baking bar finely chopped
- ⅓ cup rainbow chip crunch sprinkles
Instructions
- Preheat the oven to 350°F. Spray an 8×8 baking dish with non-stick cooking spray and line with parchment paper, set aside.
- In a large bowl, add the butter, sugar, cocoa, vanilla, eggs, milk, and corn syrup and using a hand mixer beat until smooth.
- Next, fold in the flour and salt until fully combined (make sure there are no dry patches remaining).
- Pour the batter into the prepared baking dish, smoothing out the top.
- Bake for 20-25 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and place on a wire rack to cool completely..
- Once the brownies are cool, prepare the ganache by warming the heavy cream in a small saucepan, stirring occasionally until it just comes to a simmer, you do not want this to boil.
- Remove from the heat and stir in the chocolate chips and chopped chocolate until melted and smooth.
- Pour the ganache over the brownies, then top with the sprinkles.
- Let cool for about 3 hours in the refrigerator for the ganache to set before slicing and serving.
Notes
- If you want to stray from the original recipe you can add things to the batter and top, see some of my ideas above.
- These can be frozen, see above on how to do that.
- Make sure that you use a higher quality chocolate so it melts better.
- These can easily be doubled.
- These are best served at room temperature so I suggest after chilling, return to the counter to come to room temp before serving.
Nutrition
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