Go Back
Homemade Cosmic Brownies

Homemade Cosmic Brownies

These Homemade Cosmic Brownies are an easy copycat of the nostalgic childhood treat, made with rich, fudgy chocolate brownies, silky chocolate ganache, and colorful rainbow candy-coated chocolate pieces.
Print Recipe Pin Recipe
Prep Time 20 minutes
Cook Time 25 minutes
cooling and chill time 2 hours
Total Time 2 hours 45 minutes
Servings: 12 brownies
Course: Dessert, Snack
Cuisine: American
Calories: 390
Ingredients Equipment Method Notes

Ingredients
  

Fudgy Brownies
  • 10 tablespoons unsalted butter 140 g
  • 4 ounces semi-sweet chocolate chopped
  • 1 cup ]granulated sugar 200 g
  • 1/2 cup light brown sugar, packed 100 g
  • 2 large eggs room temperature
  • 1 large egg yolk room temperature
  • 2 teaspoons vanilla extract
  • 3/4 cup unsweetened cocoa powder 75 g
  • 3/4 cup all-purpose flour 95 g
  • 1/2 teaspoon kosher salt
  • 1/4 teaspoon baking powder
  • 1 tablespoon instant espresso powder optional
  • 2 tablespoons whole milk
Chocolate Ganache
  • 1 cup semi-sweet chocolate chips 170 g
  • 1/2 cup heavy cream
  • 1 tablespoon unsalted butter
  • 1/2 teaspoon vanilla extract
  • Pinch of salt
Topping
  • 1/3-1/2 cup rainbow candy-coated chocolate pieces

Equipment

  • 8x8-inch metal baking pan
  • parchment paper
  • Nonstick cooking spray
  • Large mixing bowl
  • Medium microwave-safe bowl
  • whisk
  • Rubber spatula
  • measuring cups and spoons
  • Kitchen scale optional, but recommended
  • Fine-mesh sieve for sifting cocoa and flour
  • Small saucepan for heating heavy cream
  • Sharp knife for clean slices

Method
 

Make the Brownies
  1. Preheat the oven to 325°F. Line an 8x8-inch metal baking pan with parchment paper, leaving an overhang on the sides. Lightly spray with nonstick cooking spray.
  2. Add the butter and chopped semi-sweet chocolate to a microwave-safe bowl. Microwave in 20–30 second intervals, stirring between each interval, until melted and completely smooth. Allow to cool for 5 minutes.
  3. Whisk the granulated sugar and brown sugar into the melted chocolate mixture.
  4. Add the eggs and egg yolk one at a time, whisking well after each addition. Mix in the vanilla extract and milk.
  5. Sift in the cocoa powder, flour, kosher salt, baking powder, and espresso powder, if using.
  6. Gently fold the dry ingredients into the chocolate mixture just until no dry streaks remain. Do not overmix.
  7. Spread the brownie batter evenly into the prepared pan.
  8. Bake for 22–27 minutes, or until the edges are set and a toothpick inserted into the center comes out with moist, fudgy crumbs.
  9. Allow the brownies to cool completely in the pan for approximately 1 1/2–2 hours.
Make the Chocolate Ganache
  1. Place the semi-sweet chocolate chips in a heat-safe bowl.
  2. Heat the heavy cream until steaming but not boiling.
  3. Pour the hot cream over the chocolate and allow it to sit for 2–3 minutes.
  4. Add the butter, vanilla extract, and a pinch of salt. Stir until completely smooth and glossy.
Assemble
  1. Pour the ganache over the completely cooled brownies and spread evenly from edge to edge.
  2. Immediately sprinkle the rainbow candy-coated chocolate pieces over the ganache.
  3. Refrigerate for 30–60 minutes, or until the ganache has set.
  4. Lift the brownies from the pan using the parchment paper. Cut into 12 rectangles or 16 smaller squares and serve.

Notes

  • Do not overbake. A toothpick should have moist crumbs attached rather than coming out completely clean.
  • For extra-rich brownies, brown the butter before melting in the chocolate.
  • Allow the brownies to cool completely before adding the ganache.
  • Chill before slicing for clean, sharp edges.
  • Warm and wipe your knife between cuts for bakery-style slices.
  • Store in an airtight container at room temperature for up to 3 days or refrigerate for 5–7 days.
  • Freeze for up to 2 months.