With a thick chocolate ganache layer and colorful candies on top, these homemade cosmic brownies are the perfect nostalgic childhood treat. Plus, they’re super easy to make!

These copycat cosmic brownies are basically a 90’s American childhood in chocolate form. Topped with a thick chocolate ganache and topped with rainbow candies, these fudgy brownies are a real treat!
This is actually my second Cosmic brownie recipe. I made a different version in 2022, but I wanted to make a taller brownie that used colorful chocolate drops instead. That’s where this recipe comes in! The end result? A perfect homemade Cosmic brownie that is nearly identical to the original Little Debbie’s treat.
Why You’ll Love This Cosmic Brownie Recipe
- Simple. There are no complicated techniques or fancy ingredients in this recipe, making it perfect for all-level home cooks!
- Crowd-pleaser. Who doesn’t like brownies? You can bring them to potlucks, birthday parties, dinner parties, and all sorts of celebrations. Everyone will love them!
- Fudgy. You’ll love their moist, chocolatey intensity in every bite.
What makes cosmic brownies so good? The fudgy brownies are topped with a thick chocolate ganache and then sprinkled with crunchy rainbow candies. The combination of textures and flavors is pretty incredible!
What Are Cosmic Brownies?
Cosmic brownies are a classic American treat from Little Debbie’s. Their signature rainbow sprinkle topping and name were inspired by the colorful “cosmic” bowling trend of the 90s. The product first hit the shelves in 1999 and has since become an iconic and timeless snack in the US.
They’re soft, fudgy bite-size brownies that are topped with a thick layer of chocolate ganache. Super rich and chocolatey, cosmic brownies are the perfect snack for young and old alike.
How to Make Cosmic Brownies
Making cosmic brownies is just like making regular brownies but with a little extra love from the ganache. Here’s is a quick overview. Be sure to scroll down to the recipe card for more detailed instructions.
- Prepare the baking dish. Preheat your oven to 350°F (180°C). Grease an 8×8-inch baking pan with oil and line it with parchment paper. Don’t use larger baking pans because the brownies will come out thinner and this affects baking time.
- Make the brownie batter. Combine the dry and wet ingredients separately, then combine and mix until there are no dry bits of batter.
- Bake. Pour the batter into the prepared baking pan and smooth it with a spatula. Bake for 25-30 minutes. Don’t skip this step or you’ll end up with unevenly baked brownies.
- Make the ganache. Melt the chocolate in hot heavy cream. Let it sit for three minutes before stirring. Mix until it becomes smooth. Make sure no moisture enters the mixture, otherwise, it can separate.
- Finish the brownies. Let the brownies cool completely. Evenly spread the ganache other them and then sprinkle the rainbow chocolate drops on top. Place the brownies in the refrigerator for two hours, or until the ganache sets. Cut the brownies and serve. That’s it!
Tips for Perfectly Fudgy Brownies
- Don’t overbake. The key to fudgy brownies is removing them from the oven when the baking time is up and then letting them set at room temperature. Baking for longer can result in drier, cake-like brownies.
- Stir until just combined. Over-mixing the batter will develop the gluten and cause them to sink and become rubbery.
- Let them cool. Never try to slice freshly baked brownies. They’ll stick to the knife and you won’t get a clean cut. If you’re in a rush, wait until the baking pan is lukewarm, then place it with a kitchen towel in the fridge to chill quicker.
- Use the right baking dish. I recommend using a metal baking pan for this recipe. It heats up faster than a glass baking dish and results in more evenly cooked brownies.
How to Store & Freeze
- Fridge: Once fully cooled, refrigerate these cosmic brownies in an airtight container for up to 7 days. Keep them away from strong-smelling foods like onions to avoid the transfer of odors. Don’t store them at room temperature, especially if there’s lots of humidity and heat in your area.
- Freezer: You can also freeze them. Wrap each brownie in plastic wrap twice. Then wrap them in aluminum foil and pop them into a freezer-friendly bag or container. Freeze them for up to 2 months. When you’re ready to enjoy them, place the brownies on the counter for 15-25 minutes or until fully thawed.
More Brownie Recipes to Try
Cosmic Brownies
Ingredients
Brownies:
- ½ cup unsalted butter , melted
- 1 cup granulated sugar
- ¾ cup unsweetened cocoa powder
- 2 large eggs + 1 egg yolk , at room temperature
- 3 tablespoons vegetable oil
- 1 tablespoon light corn syrup
- 1 teaspoon vanilla extract
- ¾ cup all-purpose flour
- ¼ teaspoon kosher salt
Ganache:
- ½ cup heavy cream
- 8 oz bittersweet chocolate bar, chopped
Decoration:
- ⅓ cup rainbow chocolate drops or sprinkles for decoration
Instructions
- Prepare the baking pan. Preheat your oven to 350°F (180°C). Grease an 8×8-inch baking pan with oil and line it with parchment paper.
- Whisk the dry ingredients. Mix all-purpose flour with salt in a small bowl, and set aside.
- Mix the wet ingredients. Add the melted butter, sugar, and sifted cocoa powder to a large mixing bowl and beat until smooth. Add the eggs, yolk, oil, corn syrup, and vanilla extract, and mix until everything is fully incorporated.
- Combine the mixtures. Add the dry ingredients to the wet mixture and mix until thoroughly combined.
- Bake. Pour the batter into the prepared baking pan and smooth it with a spatula. Bake for 25-30 minutes.
- Make the ganache. In a saucepan, heat the heavy cream over medium heat until it is hot, but be sure not to bring it to a boil. Remove from the heat. Add the chocolate to the mixture. Let it sit for three minutes before stirring it until it becomes smooth.
- Finish brownies. Spread the frosting evenly over the cooled brownies, and then sprinkle the rainbow chocolate drops over the top of the ganache.
- Chill to set. Place the brownies in the refrigerator for two hours, or until the ganache sets. Once set, cut the brownies and serve.
Nutrition
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These were amazing! A keeper.
Glad you enjoyed the recipe! Thank you for coming back to let me know. 🙂
How do I make this recipe for a 9×13 pan? My elderly parents are brownie addicts . 😂
A good brownie is hard to resist! To be honest, I have not made these in a 9×13 pan. If I were going to try it, I would double the ingredients and then expect the baking time to increase a bit. So I’d bake the brownies for the indicated amount of time, test them for doneness, then continue baking in 5 minute increments until they are done. You’ll probably end up with about 30-35 minutes of baking time. For the ganache, you can just double the ingredients and proceed as directed, same with the rainbow candies. 🙂 Let me know how it goes!