Homemade Cosmic Brownies are a fun and delicious treat that reminds many of us of childhood snacks. These rich, chocolatey brownies are topped with a creamy chocolate ganache and colorful rainbow chips, making them not just tasty but also visually appealing. They are perfect for parties, after-school snacks, or simply a cozy night in. Let’s dive into this delightful recipe!

Why Make This Recipe
Making Homemade Cosmic Brownies allows you to bring a nostalgic twist to your kitchen. They are easy to make, require basic ingredients, and offer a chewy texture that pairs perfectly with the glossy ganache. Plus, you can customize them with your favorite toppings! This recipe is a great way to satisfy your chocolate cravings and impress your friends and family.
How to Make Homemade Cosmic Brownies
Ingredients:
- 6 ounces dark chocolate (chopped)
- ¾ cup unsalted butter (melted)
- 1 ¼ cup granulated sugar
- ⅓ cup dark brown sugar (packed)
- 3 large eggs (room temperature)
- ¾ teaspoon salt
- 1 tablespoon cornstarch
- ¼ teaspoon baking powder
- ¼ cup cocoa powder
- 1 cup all-purpose flour
- 1 ½ cups semi-sweet chocolate chips
- 2 tablespoons unsalted butter
- ½ cup heavy cream
- Rainbow chips or sprinkles
Directions:
- Preheat the oven to 350 degrees Fahrenheit. Grease a 9×13 inch pan and, if desired, line it with parchment paper, leaving a 1-inch overhang on both sides.
- In a large bowl, melt the chopped dark chocolate and unsalted butter together in 30-second intervals until fully melted. Stir in the granulated sugar, dark brown sugar, and eggs.
- In a medium bowl, sift together the salt, cornstarch, baking powder, cocoa powder, and flour. Add the dry ingredients to the wet mixture and mix until well combined.
- Pour the brownie batter into the prepared pan and smooth it out with a spatula. Bake for 40-45 minutes, until a toothpick inserted in the center comes out clean.
- Let the brownies cool completely in the pan.
Ganache:
- In a small saucepan, combine the semi-sweet chocolate chips, 2 tablespoons of butter, and ½ cup of heavy cream. Heat over low heat, stirring until smooth and combined.
- Pour the chocolate ganache over the cooled brownies and spread it evenly.
- Top with rainbow chips or sprinkles.
How to Serve Homemade Cosmic Brownies
Once your brownies are ready, cut them into squares and serve them on a plate. They can be enjoyed warm or at room temperature. Pair them with a scoop of vanilla ice cream or a glass of cold milk for a delightful treat!
How to Store Homemade Cosmic Brownies
Store any leftover brownies in an airtight container at room temperature for up to 3 days. If you want to keep them longer, you can refrigerate them for a week or freeze them for up to a month. Just make sure to wrap them tightly in plastic wrap before freezing.
Tips to Make Homemade Cosmic Brownies
- Make sure to use room temperature eggs for the best texture.
- Do not overmix the batter, as this can lead to dense brownies.
- You can use any kind of chocolate chips or toppings that you prefer for the ganache.
- For an extra layer of flavor, add a touch of vanilla extract to the batter.
Variation
Feel free to add nuts, such as walnuts or pecans, for added crunch. You can also substitute white chocolate chips for the semi-sweet ones if you prefer a different flavor.
FAQs
1. Can I use cocoa powder instead of dark chocolate?
Yes, you can use cocoa powder, but your brownies may be less rich. You’ll need to adjust the recipe accordingly.
2. How do I know when my brownies are done?
Insert a toothpick into the center of the brownies; if it comes out clean or with a few moist crumbs, they’re done!
3. Can I make these brownies ahead of time?
Absolutely! You can prepare the brownies in advance and store them, or even freeze them for later enjoyment.
Enjoy your baking adventure with these Homemade Cosmic Brownies!

Homemade Cosmic Brownies
Ingredients
For the Brownies
- 6 ounces dark chocolate (chopped)
- ¾ cup unsalted butter (melted)
- 1 ¼ cup granulated sugar
- ⅓ cup dark brown sugar (packed)
- 3 large eggs (room temperature) Use room temperature for best texture.
- ¾ teaspoon salt
- 1 tablespoon cornstarch
- ¼ teaspoon baking powder
- ¼ cup cocoa powder
- 1 cup all-purpose flour
For the Ganache
- 1 ½ cups semi-sweet chocolate chips
- 2 tablespoons unsalted butter
- ½ cup heavy cream
- Rainbow chips or sprinkles For topping.
Instructions
Preparation
- Preheat the oven to 350 degrees Fahrenheit. Grease a 9×13 inch pan and, if desired, line it with parchment paper, leaving a 1-inch overhang on both sides.
Mixing the Batter
- In a large bowl, melt the chopped dark chocolate and unsalted butter together in 30-second intervals until fully melted. Stir in the granulated sugar, dark brown sugar, and eggs.
- In a medium bowl, sift together the salt, cornstarch, baking powder, cocoa powder, and flour. Add the dry ingredients to the wet mixture and mix until well combined.
Baking
- Pour the brownie batter into the prepared pan and smooth it out with a spatula. Bake for 40-45 minutes, until a toothpick inserted in the center comes out clean.
- Let the brownies cool completely in the pan.
Making the Ganache
- In a small saucepan, combine the semi-sweet chocolate chips, 2 tablespoons of butter, and ½ cup of heavy cream. Heat over low heat, stirring until smooth and combined.
- Pour the chocolate ganache over the cooled brownies and spread it evenly.
- Top with rainbow chips or sprinkles.
Serving
- Cut the brownies into squares and serve them on a plate. Enjoy warm or at room temperature with a scoop of vanilla ice cream or a glass of cold milk.


