Skip to Content
Menu

Copycat Rainbow Chip Fudge Brownies

  • Pin
Updated Jun 4, 2025
  • Pin

Remember those rich, chewy Cosmic® Brownies from your childhood lunchbox? This easy Cosmic® Brownie copycat recipe brings that nostalgic treat back with a homemade upgrade that’s perfect for summer baking. Made with Betty Crocker™ Dark Chocolate Brownie Mix, melted butter, and a touch of oil, these brownies are extra fudgy and ultra-satisfying. 

Topped with silky bittersweet ganache and finished with rainbow candy sprinkles, they’re a throwback dessert you can whip up in under an hour. Whether you're craving an easy homemade brownie recipe or planning a fun summer bake, these copycats deliver all the classic flavor with a fresh, grown-up twist.

Frequently Asked Questions

Copycat Rainbow Chip Fudge Brownies

  • Prep Time 15 min
  • Total 1 hr 45 min
  • Servings 16
  • Ingredients 7
  • Pin

Ingredients

Brownies

Topping

  • 8 oz bittersweet baking chocolate, roughly chopped
  • 1/2 cup heavy cream
  • 1/4 cup rainbow candy-coated chocolate chips

Instructions

  • Step 
    1

    Heat oven to 350°F.  Lightly grease bottom of a 9-inch square baking pan or line with cooking parchment paper. 

  • Step 
    2

    In a large bowl, combine brownie mix, melted butter, vegetable oil, and eggs. Stir until well blended. 

  • Step 
    3

    Pour the batter into the prepared pan and spread evenly. Bake 28 to 32 minutes or until a toothpick inserted near the center comes out with just a few moist crumbs attached. Let the brownies cool completely in the pan.

  • Step 
    4

    While the brownies cool, make the ganache. Place chopped chocolate in a medium heat-safe bowl. Heat 1/2 cup heavy cream in the microwave on high for 45 to 60 seconds or until steaming, but not boiling. Pour the hot cream over chopped chocolate. Let sit for 1 to 2 minutes, then stir until smooth and glossy.

  • Step 
    5

    Pour the ganache over the cooled brownies and spread evenly over top with a spatula. Immediately top with rainbow candy-coated chocolate chips.

  • Step 
    6

    Let brownies stand at room temperature for about an hour to allow the ganache to set. Slice into squares and serve.

Nutrition

Nutrition Facts are not available for this recipe
  • Trademarks referred to herein are the properties of their respective owners.
© 2025 ®/TM General Mills All Rights Reserved

Reviews & Questions Section