Best Ever Copycat Cosmic Brownies

If you loved these brownies from your childhood, you’ll love the homemade version of Copycat Cosmic Brownies even more! Supremely fudgy and chewy with a decadent ganache frosting and irresistible rainbow chips.

I absolutely grew up as a snack food princess. I pretty much ate snack foods from the time I woke up to right before bed. Lest you think, “child, where were your parents and why weren’t they cooking you gourmet pancakes and things before school every day?” I will counter that they were also eating snack foods before work and didn’t have time for elaborate breakfasts. Plus, even if we did get pancakes, they came from a box or freezer.

In no way do I blame my parents – they were both working multiple jobs or going to school and honestly, growing up as a kid of convenience food wasn’t so bad. Have you even had a McMuffin? Those are some of the best things on planet Earth.

Plus, it wasn’t my parents fault entirely. Since they worked a lot, we spent a lot of time at my grandma’s house and she was usually in charge of feeding us breakfast and lunch. Since she was known to start small fires in her attempt to cook, we 99.9% of the time ate fast food, then would come home and raid her pantry for snack cakes, cookies, and other pre-packaged goodness.

Cosmic brownies were one of my favorite treats to raid because I loved the rainbow chip sprinkles on top and how fudgy they were. I didn’t realize that they would be so easy to make as an adult!

What I love about these Copycat Cosmic Brownies is how simple they are with real ingredients you can pronounce, and of course, how delicious they are! They’re super duper fudgy and chewy with a delicious chocolate flavor and the ganache frosting is so easy and incredible. The “sprinkles” are actually rainbow chocolate chips and are a complete necessity to make an authentic Cosmic Brownie! I found mine at Michael’s but Jo-Ann’s or even Amazon should have them by Wilton brand. Of course, if you don’t want to use them, regular rainbow jimmies or even chopped walnuts would be delicious.

I’ve tested this recipe using different brownie bases since Cosmic brownies have a distinct texture and found the best recipe was my One Bowl Fudge Brownie recipe with some tweaks. For starters, I added in some cornstarch to really give it that chewy, fudgy texture. I also added in an extra egg yolk for some more moisture, because moisture = fudgy brownies! I think you’re going to LOVE this recipe!

Copycat Cosmic Brownies – welcome to the modern world!

Print Recipe

4.8 from 5 votes

Best Ever Copycat Cosmic Brownies

These Copycat Cosmic Brownies are the BEST I've tried that taste even BETTER than the original ones we had as kids. Super fudgy and rich with a ganache frosting and addictive rainbow chocolate chips.

Prep Time20 mins

Cook Time30 mins

Total Time50 mins

Course: Bars

Servings: 12 -15

Author: Hayley Parker, The Domestic Rebel

Ingredients

• 1/2 cup (1 stick) unsalted butter
• 4 ounces semi-sweet chocolate such as a Baker's chocolate bar roughly chopped
• 1 cup granulated white sugar
• 2 large eggs
• 1 large egg yolk
• 2 teaspoons vanilla extract
• 1 Tablespoon cornstarch
• 1/4 cup cocoa powder I recommend Dutch process
• 1/2 cup all-purpose flour
• 1/4 teaspoon salt
• FOR THE FROSTING:
• 1 & 1/2 cups semi-sweet chocolate chips
• 1/2 cup heavy whipping cream
• 1/4 - 1/3 cup Wilton rainbow crunch chips or you can use rainbow sprinkles, miniature M&M's candies, or even chopped walnuts

Instructions

• Preheat oven to 350 degrees F. Line a 8x8 or 9x9 inch square baking pan with foil, extending the sides of the foil over the edges of the pan. Spray the foil liberally with cooking spray; set aside.
• In a medium saucepan over medium-low heat, add in the butter and chopped chocolate bar and stir constantly until melted and smooth, about 5 minutes. Set aside off heat to cool for about 5 minutes, then whisk in the granulated sugar and mix well. Beat in the eggs, one at a time, followed by the egg yolk and vanilla. Lastly, add in the cornstarch, cocoa powder, flour, and salt and mix well. Spread the batter into the prepared pan in an even layer.
• Bake for 25-30 minutes or until a toothpick inserted near the center comes out clean or with moist, not wet, crumbs. Cool completely in the pan.
• Once cooled, make your ganache frosting. Add the heavy cream to a microwaveable medium bowl and microwave for about 60 seconds. Add the chocolate chips to the hot heavy cream and let set undisturbed in the microwave for about 3 minutes to allow chocolate chips to soften and melt. Whisk the ganache until smooth and glossy, then spread it evenly over the brownies in the pan. Sprinkle liberally with the rainbow chips.
• Refrigerate the brownies for at least 1-2 hours before cutting or until the frosting has set. Brownies will keep for a week in the fridge or 3 days at room temperature.

You are going to LOVE how extremely fudgy and super chocolaty these addictive brownies are!

Want more brownies? Check out these other brownie recipes!

French Silk Pie Brownies

Mint Chocolate Brownies

Beer-Spiked Brownies with Poured Pecan Frosting

Have a super sweet day!

xo, Hayley