Updated
Cosmic Brownies are just like the childhood treats you loved, but even better! Homemade fudgy brownies are topped with a layer of sweet chocolate frosting and speckled with colorful candies.

Pin this recipe for later!
Pin ItCosmic Brownie
These homemade brownies are chewy and thin, just like the Little Debbie snacks you know and love. The frosting on top is so smooth, chocolatey, and perfectly sweet! Of course, what really makes these brownies cosmic in appearance is the sprinkle of rainbow candy-coated chocolate chips on top.
This cosmic brownie recipe closely follows the iconic snack, but you can also make it your own with some simple modifications. Add a few drops of peppermint, coconut, or almond to the batter, or swirl in peanut butter, Caramel Sauce, Nutella, Cookie Butter, marshmallow fluff, or even cream cheese. You could also add some of the rainbow candy-coated chocolate chips into the batter for more fun color, or stir in chocolate chips or nuts. The options are endless!
Cosmic Brownies Recipe
Equipment
- Kitchen Scale (optional)
- 9×9-inch Baking Pan
Ingredients
- ¾ cup all-purpose flour 90 grams, for gluten-free use a 1-1 flour
- ⅔ cup unsweetened cocoa powder 56 grams
- 12 tablespoons unsalted butter 170 grams, melted (1½ sticks), salted works too, if using omit the kosher salt
- 1 cup granulated sugar 200 grams, or use brown sugar
- ½ cup brown sugar 107 grams
- 2 large eggs 50 grams, room temperature
- 1 teaspoon pure vanilla extract 4 grams
- ¾ teaspoon kosher salt
- 1 cup chocolate chips 170 grams, milk, semisweet, or dark chocolate chips all work
- ½ cup heavy cream 114 grams
- ¼ cup rainbow candy-coated chocolate chips 43 grams, for topping, use mini M&M's or rainbow sprinkles instead
Instructions
- Preheat oven to 325°F. Spray a 9×9-inch baking pan with nonstick spray and line it with parchment paper. Set aside.
- In a medium bowl, whisk the flour and cocoa powder together.¾ cup all-purpose flour, ⅔ cup unsweetened cocoa powder
- In a separate larger bowl, whisk the butter and sugars together.12 tablespoons unsalted butter, 1 cup granulated sugar, ½ cup brown sugar
- Add in the eggs, vanilla extract, and salt.2 large eggs, 1 teaspoon pure vanilla extract, ¾ teaspoon kosher salt
- Add the flour mixture to the wet ingredients and stir until just combined. Do not overmix the batter; otherwise, your brownies may come out tough.
- Pour the batter into the pan, and use a spatula to spread it out.
- Bake for 30-35 minutes, or until a toothpick comes out nearly clean. Allow brownies to cool.
- While the brownies are baking, place 1/2 cup of heavy cream in a pot and add 1 cup of chocolate chips. Heat, stirring until the chocolate is melted and smooth.1 cup chocolate chips, ½ cup heavy cream
- Spread the frosting out over the brownies. Then, sprinkle rainbow chips over the frosting.¼ cup rainbow candy-coated chocolate chips
- Refrigerate or freeze to let the frosting set before enjoying!
Becky’s Tips
- You can use a neutral oil, such as vegetable, canola, or coconut oil, in place of the butter, but your brownies may not turn out as soft.
- Do NOT skip lining your pan. A parchment paper sling will help you to remove the brownies from the pan.
- To cut these brownies cleanly, dip a knife in hot water, then wipe it off between slices.
Nutrition information is automatically calculated, so should only be used as an approximation.
How to Make Cosmic Brownies Step by Step
Get the oven going and prepare a baking pan: Preheat oven to 325°F. Spray a 9×9-inch baking pan with nonstick spray and line it with parchment paper. Set aside.
Combine the flour and cocoa: In a medium bowl, whisk 3/4 cup of flour and 2/3 cup of cocoa powder together.
Cream the butter and the sugar: In a separate larger bowl, whisk 12 tablespoons of butter, 1 cup granulated sugar, and ½ cup brown sugar.
Stir in the remaining ingredients: Add 2 large eggs, 1 teaspoon of vanilla extract, and 3/4 teaspoon of salt.
Combine the wet and dry ingredients: Add the flour mixture to the wet ingredients and stir until just combined.
Pour into the pan: Pour the batter into the pan, and use a spatula to spread it out.
Bake and cool: Bake for 30-35 minutes, or until a toothpick comes out nearly clean. Allow brownies to cool.
Make the ganache: While the brownies are baking, place 1/2 cup of heavy cream in a pot and add 1 cup of chocolate chips. Heat, stirring until melted and smooth.
Frost the brownies: Spread the chocolate ganache over the brownies and sprinkle 1/4 cup rainbow chips over the frosting.
Refrigerate and enjoy: Refrigerate or freeze to let the frosting set before enjoying!
Storage
Store leftover cosmic brownies in an airtight container in the refrigerator for up to 5 days. Although they are safe to store at room temperature, I do not recommend it, as the frosting tends to melt off in warmer temperatures. Bring the brownies to room temperature for about 10 minutes before serving.
You can bake these up to 1 day in advance and frost them on the day you plan to serve them. Store the unfrosted brownies in an airtight container at room temperature until ready to frost and serve.
Freeze cosmic brownies cut into individual slices and wrapped in 2 layers of plastic wrap and 1 layer of aluminum foil for up to 2 months. Let thaw at room temperature before serving.
Serving Suggestions
Serve these with a scoop of Red Velvet Ice Cream or creamy White Chocolate Mousse. You can also pair the brownies with these No-Bake Cheesecake Cups, or Chocolate Pots de Creme for an even more indulgent dessert.