I’m thrilled to share this indulgent Homemade Cosmic Brownies recipe—dense, ultra-fudgy brownies topped with glossy chocolate ganache and sprinkled with colorful candy-coated chocolate chips. It’s the perfect nostalgia treat reminiscent of classic store-bought cosmic brownies, but so much better.

Homemade Cosmic Brownies

Why You’ll Love This Recipe

I love how these brownies deliver that nostalgic chocolatey bite, yet are richer and more homemade. The fudgy texture combined with a shiny ganache and a pop of color from the candy chips makes them irresistible. They impress at parties and are great for satisfying a sweet craving.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

For the Brownies (makes ~24 bars)

1 cup unsalted butter, melted and slightly cooled
1 ¾ cups granulated sugar
½ cup light brown sugar
3 large eggs + 1 egg yolk, room temperature
1 teaspoon vanilla extract
1 cup unsweetened cocoa powder
1 cup all-purpose flour
½ teaspoon salt

For the Ganache

8 oz semisweet chocolate, finely chopped
½ cup heavy cream
1 tablespoon light corn syrup (optional, for shine)

For Topping

Rainbow candy-coated chocolate chips (mini M&Ms or similar)

Directions

Prepare the brownies
I preheat the oven to 350°F and line a 9×13″ pan with parchment, leaving overhang for easy removal. I whisk melted butter with both sugars, then add eggs, yolk, and vanilla. I sift in cocoa, flour, and salt, stir just until combined, and pour into the pan. I bake until a toothpick shows moist crumbs, about 27–33 minutes.
Cool completely
I let the brownies cool fully—this is crucial for a clean ganache layer to se.
Make the ganache
I place chopped chocolate and corn syrup in a bowl. I heat cream until steaming, pour over chocolate, let rest 1–3 minutes, then whisk until smooth and glossy. If needed, I microwave briefly in short bursts.
Frost the brownies
I spread the warm ganache over cooled brownies, then sprinkle the candy chips before it sets.
Chill and slice
I refrigerate for 1–2 hours until the ganache firms up. Then I use a warm, dry knife and wipe it clean between cuts for tidy bars.

Servings and timing

Serves: ~24 brownies
Prep Time: 30 minutes
Cook Time: 30 minutes
Chill Time: 1–2 hours
Total Time: about 3 hours

Variations

I stir mini chocolate chips or chopped nuts into the batter before baking for extra texture.
I swap candy chips for rainbow sprinkles if I can’t find the minis.
For even richer brownies, I use partly Dutch-process cocoa and melt in some dark chocolate in the batter.

Storage/reheating

I store leftovers in an airtight container in the fridge for up to 5 days. If I want to freeze, I slice, wrap tightly in plastic, and freeze up to 3 months—thaw overnight in the fridge. The ganache stays firm when chilled and is best enjoyed cold or at room temp.

FAQs

Can I halve this recipe?

Yes—use an 8×8″ pan and half all ingredients. Bake time is about 25–30 minutes, until moist crumbs appear.

Why use corn syrup in ganache?

It adds glossy shine and gives the ganache that classic cosmic brownie look, but you can omit it if unavailable.

How do I get clean slices?

I ensure brownies are completely cool and ganache is set, then use a hot, dry knife wiped between cuts—this really helps.

Can I make them ahead?

Absolutely—I bake in advance and frost same day or frost and slice up to 24 hours before serving.

Are they freezer-friendly?

Yes—slice, wrap, and freeze. Thaw overnight in the fridge before enjoying.

Conclusion

These Homemade Cosmic Brownies are a fun, decadent twist on a beloved nostalgia treat. They’re rich, chocolatey, and bursting with joyful color. I love how easy they are and how they always impress at gatherings. I hope you love baking (and devouring) them as much as I do!