This homemade Cosmic Brownie recipe is a copycat version of Little Debbie's famous treat. A chewy decadent brownie topped with a rich chocolate ganache and rainbow chips. If you liked the classic rainbow sprinkle brownies, you'll love this upgraded version even more!
Preheat the oven to 350°F. Line a 9x13 inch baking dish with parchment paper and spray with cooking spray. Set aside.
To a large bowl, add the granulated sugar, brown sugar, vanilla, salt, whole eggs and yolks and whisk until combined.
1 cup granulated white sugar, 1 cup brown sugar, 2 teaspoons vanilla extract, 1/2 teaspoon salt, 2 large eggs, 2 large egg yolks
To a microwave safe bowl, add the butter and chocolate chips. Microwave for 30 seconds, stir, then microwave another 30 seconds and stir. Repeat until melted and smooth.
Whisk in the vegetable oil to the melted chocolate.
½ cup vegetable oil
Pour the chocolate mixture into the sugar mixture and mix until fully combined. Gently fold in the flour and cocoa.
1 ¼ cups all-purpose flour, ¼ cup unsweetened cocoa powder
Pour the brownie batter into the prepared pan and bake until a toothpick inserted in the center comes out clean, 30 to 35 minutes.
To make the ganache
Pour the heavy cream into a microwave safe bowl and heat for 1 minute.
½ cup heavy cream
Pour the chocolate chips into the heated cream and let stand for 2 minutes. After the time is up, stir until the chocolate is melted and smooth.
1.5 cups chocolate chips
Pour the ganache over the brownies, spreading evenly with an offset spatula, and immediately sprinkle with the rainbow chips.
¼ cup Rainbow Chocolate Chips
Let cool completely before slicing.
Video
Notes
I use and recommend Ghirardelli 60% baking chips in both the batter and the ganache.
Once set, slice into 12-18 brownies, depending on how generous you'd like to make them.
Store leftovers covered in the fridge for up to 4 days.
For an alternate frosting that will set and not need to be chilled, use 4 Tablespoons unsalted butter, 1/2 cup sweetened condensed milk, and 8 ounces of chocolate chips. Heat in a microwave safe bowl and pour over the brownies.