The Best Cosmic Brownies Recipe

These brownies are made slightly differently than you’d expect from a normal brownie. Since we’re using a smooth ganache topping, we’ don’t need’ll use the standard ingredients that give regular brownies their signature crinkly and crackly top but instead, these brownies will turn out much softer, almost melt in your mouth. They’re not underbaked or anything; they’re just more pillowy so that the texture blends more evenly with the ganache. I know you’re here for this large batch, but just in case you want something a little smaller, my small batch cosmic brownies exist!

Some ganaches are too rich in flavor and have a somewhat grainy in texture. Not this ganache. It has a perfectly balanced amount of chocolate flavor and an incredibly silky smooth texture that, when combined with the brownie base, creates a cloud-like mouth-feel that is somewhat indescribable. And to top it all off, you get these beautiful chocolate rainbow sprinkles that add a gorgeous pop of color, a fun textural crunch, and a heartfelt sense of nostalgia for those of us who had the cosmic brownies as kids.

Since you are here and love brownie recipes, check out these Small Batch Brownies, these Brownie Cookies, or this Cookie Butter Brownies Recipe.

Ingredients for this Copycat Cosmic Brownies Recipe

Here are the ingredients you will need to make this homemade version of the classic cosmic brownie. Scroll down to the recipe card at the bottom of the page for the detailed ingredient measurements. 

Brownie Base

• Unsalted Butter: delivers moist crumbs and that classic texture of fudgy brownies.
• Granulated Sugar and Brown Sugar: sweetens the brownies.
• Dutch-Process Cocoa Powder: is the main ingredient that provides an intense chocolate flavor and deep color that’s most similar to the Little Debbie brownies.
• Salt: balances the sweetness and enhances the chocolate flavor.
• Vanilla Extract: adds a strengthening touch to the chocolate flavor.
• Large Eggs: bind the ingredients together and contribute to the fudgy texture and richness of the homemade brownies. You will want these to be at room temperature.
• All-Purpose Flour: provides structure and helps the brownies hold their shape.
• Cornstarch: adds a tender, chewy texture to counteract the dense brownie base by softening the flour’s gluten development.

Rich Chocolate Ganache Topping

• Heavy Cream: helps melt the chocolate and creates a smooth chocolate ganache frosting.
• Semisweet Chocolate Bar: forms the glossy topping that sets into a fudgy layer. You will want to use high quality chocolate for the best flavor, also make sure that it’s chopped so it melts evenly.
• Pinch of Salt: deepens the chocolate flavor and adds balance to the sweetness.
• Candy-Coated Rainbow Chocolate Chips: adds the signature cosmic brownie look.

How to make this Homemade Cosmic Brownies Recipe

This is how you can make this copycat version of Little Debbie’s Cosmic Brownies. Make sure to scroll down to the recipe card at the end of this post for the oven temp, bake time, and full step-by-step instructions! 

1. Preheat your oven and line an 8×8-inch baking pan with parchment paper, leaving a bit of overhang for easy removal.
2. In a medium saucepan, melt the butter on the stove. Once melted stir in the granulated sugar, brown sugar, cocoa powder, and salt until the mixture is well blended and smooth.
3. Next, transfer everything to a large bowl and whisk in the vanilla extract. Add the eggs one at a time, beating until the batter becomes thick and shiny.

1. Gently fold in the flour and cornstarch just until the dry ingredients are incorporated.
2. Pour the brownie batter into the prepared pan and smooth it out evenly. Bake until the edges are set and the center is just a little jiggly. Allow to cool completely in the pan.
3. Once cool, flip the brownies and remove the parchment paper. To get an even flat surface, we will be adding the chocolate to the bottom layer of the brownies for a cleaner look.

1. Warm the heavy cream in the microwave for about 30 seconds, until hot but not boiling. Pour it over the chopped chocolate and let it sit for a minute to soften.
2. Add a pinch of salt, then stir until the melted chocolate mixture is smooth and glossy.
3. Spread the ganache evenly over the cooled brownies in an even layer using an offset spatula.
4. While the ganache is still soft, sprinkle the rainbow chips over the top.
5. Refrigerate the brownies until set. For clean slices, use a sharp knife and wipe it clean between each cut. Enjoy!

Tips and Tricks for the Best Flavor

• Spend a couple of dollars more if you can to use a high-quality chocolate for the ganache.
• Use Dutch-process cocoa for a more classic chocolate flavor and that signature dark color.
• Don’t skip the cornstarch and don’t try to substitute for it. These chewy brownies need it!
• Use room temperature eggs so they mix in smoothly.
• Be careful not to overbake. You want to pull the brownies out when the edges are set, but the center still has a very slight jiggle. They may not look done at first, but they’ll continue to cook as they cool.
• Use a kitchen scale instead of a measuring cup to weigh your ingredients for better accuracy. Do this specifically for the flour.

Why do you need to make this fudgy Cosmic Brownies recipe?

• Eating cosmic brownies as an adult will transport you back to your elementary school lunches (in the best ways!).
• This great recipe only requires simple ingredients that you can find at any local grocery store.
• This might be a hot take, but I would say this special treat tastes even better than the store-bought version.
• It’s bound to become one of your new favorite desserts once you taste it.

Frequently Asked Questions – FAQ

Can I add slightly different flavor variations to this cosmic brownies recipe?

• Add a tablespoon or two of instant espresso powder for a chocolate-coffee flavor combo.
• Use dark chocolate instead of semi-sweet chocolate to make dark chocolate brownies if you want less sweetness.
• Mix in a teaspoon of cinnamon or throw in a handful of peanut butter chips for a unique flavor twist.
• Add other toppings alongside the rainbow chip sprinkles.

Can I use regular cocoa powder instead of Dutch-processed powder?

You can use regular unsweetened cocoa powder, but the Dutch-process gives a deeper chocolate flavor and a darker color that more closely resembles the original Cosmic Brownie.

Can I make these ahead of time?

Yes! This cosmic brownies recipe stores really well. You can make them a couple of days in advance and store them in an airtight container in the fridge.

How do I store leftovers of this homemade cosmic brownie recipe?

Put your leftovers in an airtight container and keep them in the refrigerator. They should last for up to 3 or 4 days.

Can I freeze them?

Absolutely, and they actually freeze very well! To do so, wrap each slice or individual piece tightly in plastic wrap first to prevent any air from getting in. Then you can place them in the freezer like that or extra protected by putting the wrapped pieces in an airtight container or zip-top bag. They should last in the freezer for at least a month or two.

Can I make a gluten-free version of this copycat Little Debbie cosmic brownies recipe?

You can, as long as you’re using a gluten-free flour blend like the one from King Arthur or Bob’s Red Mill. Just know, however, that they won’t have the same texture as the real thing unfortunately.

Can I use semi-sweet chocolate chips instead of a chocolate bar?

A chopped chocolate bar is best for chocolate frosting because it melts and spreads more easily, as it doesn’t have the emulsifiers that chocolate chips have. Chocolate chips are designed to melt but not spread as much so if you use it for the chocolate icing, the texture just might not be the same.

The Best Cosmic Brownies Recipe