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Homemade Cosmic Brownies

A nostalgic, ultra-fudgy copycat recipe for Little Debbie Cosmic Brownies. Featuring a dense, chewy chocolate base topped with a rich chocolate ganache and iconic rainbow crunch sprinkles.
Print Recipe
Prep Time 20 minutes
Cook Time 25 minutes
Total Time 1 hour 45 minutes
Servings: 16 brownies
Course: Dessert, Snack
Cuisine: American, Retro
Calories: 310
Ingredients Equipment Method Notes

Ingredients
  

Brownie Base
  • 0.75 cup unsalted butter melted and cooled
  • 1 cup granulated sugar
  • 0.33 cup light brown sugar packed
  • 2 eggs large
  • 2 tsp vanilla extract
  • 0.75 cup all-purpose flour
  • 0.66 cup unsweetened cocoa powder Dutch-process preferred
  • 1 tbsp cornstarch
  • 0.25 tsp salt
Ganache Topping
  • 1.5 cups semi-sweet chocolate chips
  • 0.5 cup heavy cream
  • 0.5 cup rainbow candy chips or mini M&Ms

Equipment

  • 8x8 inch baking pan
  • Mixing bowls
  • Whisk
  • Small Saucepan

Method
 

  1. Preheat oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper, leaving an overhang.
  2. In a large bowl, whisk together melted butter, granulated sugar, and brown sugar until combined and glossy.
  3. Add eggs and vanilla extract; whisk until just combined. Do not overmix.
  4. Sift in flour, cocoa powder, cornstarch, and salt. Gently fold into the wet ingredients with a spatula until no flour streaks remain.
  5. Pour batter into prepared pan and smooth top. Bake for 22–25 minutes until a toothpick comes out with moist crumbs.
  6. Cool brownies completely in the pan on a wire rack.
  7. For ganache: Heat heavy cream in a saucepan until simmering. Pour over chocolate chips in a bowl. Let sit 5 minutes, then whisk until smooth.
  8. Pour warm ganache over cooled brownies. Spread evenly and sprinkle immediately with rainbow chips.
  9. Refrigerate for at least 1-2 hours to set the ganache before slicing.

Notes

Store in the refrigerator for the best fudgy texture.