Homemade Cosmic Brownies
Featuring a rich brownie base, a fudgy chocolate glaze, and a scattering of candy-coated rainbow chips, this copycat Cosmic Brownie recipe takes everything you love about the classic and makes it 100 times better!
What are Cosmic Brownies?
Produced by the Little Debbie snack company, Cosmic Brownies are a nostalgic lunchbox staple for any 90’s or 2000’s kid. These individually-packaged treats are made of a chewy brownie base with fudge frosting and candy-coated rainbow chips. Supposedly, their colorful decoration is meant to resemble the neon lights in cosmic bowling (hence the name “Cosmic Brownies”)!
However, like most childhood sweets, Cosmic Brownies are much sweeter and more artificial tasting than I remember—luckily, today’s version is a little more suited for the adult palate! For my version, we’re using great-quality ingredients and real chocolate for an ultra-fudgy brownie base. I’ve also included two different topping options (either a rich ganache or traditional fudge frosting) depending on your preference and skill level. But no matter which one you pick, the resulting brownies will be infinitely more decadent and delicious than store-bought!
Ingredients You’ll Need
Chances are, you already have most ingredients for these brownies in your pantry. Here’s what you’ll need:
- Butter. Butter keeps the brownies soft and chewy and offers a much better flavor than oil-based brownies.
- Cocoa powder. Compared to natural cocoa, dutch-processed has a smoother chocolate taste and lower acidity, since it’s been treated with an alkaline solution to neutralize the pH. All in all, this results in a richer, more chocolatey brownie.
- Espresso powder, vanilla extract, and salt. To enhance the brownies’ flavor.
- Granulated sugar and brown sugar. Using a mix of both ensures that the brownies have a chewy interior and crackly top.
- Eggs and egg yolk. Since egg yolks have more fat than the white, adding an additional yolk makes the brownies extra chewy and fudgy.
- Light corn syrup. Just a tablespoon of corn syrup adds the right amount of chew for a Cosmic Brownie texture.
- Milk or semisweet chocolate. Use whichever you prefer for sweetness!
- All-purpose flour. Flour absorbs excess water and will hold the brownies together.
- Cornstarch. Cornstarch not only thickens the batter, but it inhibits gluten formation to create the perfect chewy brownie.
- Unsweetened chocolate and whole milk. For the fudge topping.
- Candy coated rainbow sprinkles. What makes a Cosmic Brownie a Cosmic Brownie! This ingredient is pretty difficult to find in stores, so I got mine on Amazon.
Which Cosmic Brownie Glaze to Use?
For this recipe, I’ve included two different topping options you can choose from. While I could’ve gone with one and called it a day, I wanted to give you a choice depending on your skill level and preference!
Option #1: Ganache. To make the ganache, all you have to do is mix together warm heavy cream and chocolate until a smooth glaze forms, then decorate the brownies as desired. The ganache-topped brownies are much easier than version #2, though they’re significantly richer and more chocolatey than a classic Cosmic Brownie. The ganache also requires refrigeration, since it will not fully set at room temperature.
Option #2: Fudge Frosting. This version involves boiling sugar, milk, and chocolate over the stove (similar to traditional fudge-making). The resulting topping is much closer to the orignial Cosmic Brownie—it’s sweet but less rich than the ganache topping and sets hard at room temperature. However, since it involves cooking sugar to a specific temperature, this method is more temperamental and fussy than a ganache.
So, which one should you choose?
- For a traditional Cosmic brownie topping that’s fudgy, not too rich, and firm at room temperature, go with the fudge frosting version! It requires more technical skill but will produce the perfect Cosmic brownie copycat.
- For a topping that’s super easy and approachable, go with the ganache! It will be a bit richer than a traditional Cosmic brownie but will taste delicious nonetheless.
Tips and Tricks for the Best Cosmic Brownies
- Properly measure the ingredients. For perfectly fudgy Cosmic Brownies, it’s essential that you measure your dry ingredients correctly. I prefer to measure everything with a kitchen scale, but you can also spoon and level your dry ingredients into measuring cups to ensure accuracy.
- Use the right pan. My favorite baking dish for brownies is this USA 8×8 pan. I always recommend metal pans for brownies, since they conduct heat quicker than glass and won’t bake unevenly on the edges.
How to halve or double the recipe. If you’re baking for a crowd, this is the perfect recipe to make! Just double all of the recipe ingredients and bake the brownies in a 9×13 pan. If you want to make a small-batch recipe, halve the ingredients and use a 9×5 loaf pan instead. Whatever you do, keep an eye on the cook time so you don’t over or underbake the brownies!
How to Cut Perfect Brownies Every Time
One of the hardest parts about making brownies is cutting them, but here are my top tips and tricks for getting perfectly sliced brownies every time:
- Cool the brownies completely. Or better yet, let them chill in the fridge! Unless the brownies are completely cooled, they’ll flatten in between slices.
- Use a sharp, straight-edged knife. In my experience, a knife with a straight blade works much better than a serrated knife, since the brownies have less surface area to stick to.
- Run the knife under hot water. A warm knife slices through the brownies much smoother and prevents any chocolate from sticking.
- Clean in between cuts. Especially because of their fudgy texture, brownies may get messy. For the cleanest cuts, rinse your knife in between slices.
How to Store Homemade Cosmic Brownies
Depending on which glaze you choose, you should store the brownies in the fridge or at room temperature.
- If using the ganache, store the brownies in the fridge, otherwise the ganache will stay soft at room temperature. If stored in an airtight container, these brownies will last up to 3 days at room temperature or in the fridge for 1 week.
- If using the fudge frosting. Cosmic brownies with fudge topping are best stored in an airtight container at room temperature for up to 3 to 4 days, though they will last in the fridge for up to 1 week.
If you have any questions or recipe suggestions for what I should recreate next, leave them in the comments—otherwise, happy brownie baking!
Homemade Cosmic Brownies
Ingredients
For the cosmic brownie base
- 10 tablespoons unsalted butter
- ¼ cup cocoa powder, preferably dutch-processed
- A pinch espresso powder (optional)
- ¾ cup granulated sugar
- ¼ cup light brown sugar
- 1 teaspoon vanilla extract
- 2 large eggs
- 1 egg yolk (optional)
- 1 tablespoon light corn syrup (optional)
- 4 ounces chopped milk or semisweet chocolate
- ⅔ cup all-purpose flour
- 1 tablespoon cornstarch
- 1 teaspoon kosher salt
For the ganache topping (Option 1)
- 2 ounces chopped semisweet chocolate
- 2 ounces chopped milk chocolate can substitute with more semisweet chocolate and vice versa
- ¼ cup heavy cream
- A pinch of salt
For the traditional fudge topping (Option 2)
- ¾ cup granulated sugar
- 1 tablespoon unsweetened cocoa powder
- 6 tablespoons whole milk
- ¾ ounce unsweetened chocolate
- A pinch of salt
- A dash vanilla extract
- 2 tablespoons unsalted butter, cubed
Instructions
To make the cosmic brownies:
- Preheat the oven to 325°F, then lightly grease and line a 9×9 square baking pan with parchment paper.
- In a large bowl, sift together the ⅔ cup flour, 1 tablespoon cornstarch, and 1 teaspoon salt. Set aside.
- In a medium bowl, heat the 10 tablespoons of butter in 30 second increments until melted and very hot (be careful not to let the butter pop or explode).
- Whisk in the ¼ cup cocoa powder and pinch of espresso powder until well combined, then set aside to bloom for at least 5 minutes.
- Add the ¾ cup granulated sugar and ¼ cup brown sugar to the butter, whisking until well incorporated and very smooth, around 2 minutes.
- Crack in the eggs one at a time followed by the egg yolk, then add 1 teaspoon of vanilla extract and 1 tablespoon corn syrup. Whisk until smooth.
- In a separate small bowl, heat the 4 ounces of chocolate in the microwave or over a double boiler, stirring every 30 seconds until melted. Allow the chocolate to cool slightly before adding to the egg and sugar mixture. Mix until homogeneous.
- Using a rubber spatula, fold in the dry ingredients until just combined and no streaks of flour remain. Pour the brownie batter into the prepared pan—it will be thick, so use an offset spatula or knife to spread it into an even layer.
- Bake for 35-40 minutes or until the brownies are puffed and set in the middle; if you insert a toothpick into the center of the pan, a few moist crumbs should stick to it, but not raw batter (the brownies will continue to cook and set as they cool).
- Remove the brownies from the oven, then carefully bang the pan on the counter a few times to deflate and flatten the top. Set aside to cool completely.
- In the meantime, make the cosmic brownie glaze; the ganache topping option is very easy and rich-tasting but will stay soft at room temperature. The fudge frosting option requires more technical skill but has an authentic Cosmic brownie taste and stays firm at room temperature.
To make the ganache topping (Option 1):
- Place the 2 ounces of chopped milk chocolate, 2 ounces of chopped semisweet chocolate, and a pinch of salt into a heat-safe bowl and set aside.
- To make the ganache, heat the ¼ cup cream in a small saucepan over medium heat until it begins to gently simmer. Alternatively, you can heat the cream in the microwave for 30 to 60 seconds.
- Immediately pour the cream over the chocolate, making sure that each piece is submerged. Let the bowl stand for 2 minutes to soften, then stir with a silicone spatula until smooth.
- Pour the ganache over the cooled brownies and use an offset spatula or knife to spread into an even layer. Sprinkle over the candy-coated rainbow chips.
- Refrigerate the brownies for 1 to 2 hours, or until the ganache is set, before lifting out of the pan.
- Use a sharp knife to slice the brownies into 8 even pieces (for traditional Cosmic Brownie bars) or 16 even squares (for smaller brownies).
- Cosmic brownies with ganache are best stored in the fridge, since the topping will remain soft at room temperature. The brownies will last up to 3 days at room temperature or in the fridge for 1 week.
To make the fudge frosting (Option 2):
- In a small saucepan, melt the ¾ cup granulated sugar, 1 tbsp cocoa powder, 6 tablespoons whole milk, salt, and vanilla over low heat until the sugar is dissolved, around 5 minutes.
- Bring the mixture to a boil and cook without stirring for one minute. As the mixture cooks, brush down the sides of the pan with warm water and a pastry brush to dissolve any sugar crystals, then turn off the heat.
- Add in the chocolate (¾ ounce) and stir until melted and smooth.
- Place the pan back over medium heat. Without stirring, cook the chocolate mixture until it registers 238℉ on a candy thermometer, around 10 minutes. Continue to brush down the sides of the pan with water as necessary to prevent the fudge from crystallizing.
- Immediately pour the fudge mixture into a clean bowl and top with the 2 tablespoons of cubed butter, but do not stir. Let the fudge cool at room temperature until it reaches 120 to 130℉, around 20 minutes.
- Once cooled, use a wooden spoon or spatula to beat the mixture for 3 to 5 minutes, until the butter is fully incorporated and a thick, glossy, fudge glaze has formed and is just beginning to lose its sheen.
- Immediately pour the fudge topping over the cooled brownies and use an offset spatula or knife to spread into an even layer. Quickly sprinkle over the candy-coated rainbow chips, as the frosting will set quickly.
- Let the brownies sit at room temperature until the frosting is fully set before lifting out of the pan.
- Use a sharp knife to slice the brownies into 8 even pieces (for traditional Cosmic Brownie bars) or 16 even squares (for smaller brownies).
- Cosmic brownies with fudge topping are best stored in an airtight container at room temperature for up to 3 to 4 days, though they will last in the fridge for up to 1 week.
