These homemade Cosmic Brownies are richer, fudgier, and chewier than the store-bought version! This is a grown-up dark chocolate treat wrapped in a nostalgic package, perfect for satisfying any sweet tooth.
Preheat the oven to 350°F. Lightly grease an 8x8-inch baking pan with butter or baking spray and line it with parchment paper.
In a small saucepan, combine the butter and chopped chocolate. Place over medium-low heat and cook, stirring occasionally, until both are fully melted. Transfer the mixture to a large mixing bowl.
Add the granulated sugar, brown sugar, cocoa powder, and vanilla and whisk vigorously until smooth. Add the eggs and egg yolk one at a time, whisking until each one is combined before adding the next.
Add the flour, cornstarch, and salt and gently fold the dry ingredients into the chocolate mixture using a silicon spatula until no dry streaks remain. Transfer the batter to the prepared pan and smooth it into an even layer.
Bake for 35 to 40 minutes or until the edges are set and a toothpick inserted in the center comes out with a few moist crumbs. Let the brownie layer cool completely in the pan.
For the Frosting:
Place chocolate chips in a medium heatproof bowl and set aside.
Heat the cream in a small saucepan over medium-low heat until very steamy, 1 to 2 minutes. (Do not boil.) Pour the hot cream over the chocolate chips, and set aside for 5 minutes for the chocolate to melt.
Stir the chocolate and cream together until fully combined and smooth. If a few pieces of chocolate remain, microwave at 50% power for 10 seconds at a time, then stir until smooth.
Pour the frosting over the cooled brownies and spread it into an even layer. Refrigerate for 20 minutes or until frosting is mostly set but not hard on top. Sprinkle the candy-coated chips on top. Chill for another 10 minutes before slicing.
Notes
Use the parchment to lift the brownie slab out of the pan for easier slicing. This will help cut even, clean slices, and you won't risk damaging your pan with a sharp blade.