Cosmic Brownies Recipe

Cosmic brownies are one of those childhood treats that actually taste better when you make them from scratch!

Trust me on this! You need a really fudgy brownie base that’s almost undercooked in the center, or the ganache topping will overpower everything.

I use a thick chocolate ganache for the top layer and those mini rainbow chips to get that iconic look everyone remembers.

They’re rich enough that one brownie actually satisfies your sweet tooth!

Let the brownies cool completely before adding the ganache or it’ll just melt right into the brownie and ruin that clean top layer!

How to Make Cosmic Brownies Recipe

Ingredients

• 1 cup All-Purpose Flour
• 3/4 cup Cocoa Powder (unsweetened)
• 1/2 tsp Kosher Salt
• 1/2 cup Vegetable Oil
• 1 cup Brown Sugar (packed)
• 1/2 cup Granulated Sugar
• 4 tbsp Unsalted Butter (melted)
• 3 large Eggs
• 1 tbsp Light Corn Syrup
• 1 tsp Vanilla Extract
• 1 cup Semisweet Chocolate Chips
• 6 tbsp Heavy Cream
• 1/3 cup Rainbow Candy-Coated Chocolate Chips

Step-by-Step Instructions

Step 1:

Preheat your oven to 350°F.

Line a 9 x 9 inch pan with parchment paper, leaving some overhang so you can lift them out.

Whisk flour, cocoa powder, and salt in a bowl until everything looks evenly mixed.

Step 2:

Stir vegetable oil, brown sugar, granulated sugar, and melted butter together in a separate bowl until smooth.

Add eggs, corn syrup, and vanilla, then mix until the batter turns glossy and thick.

Step 3:

Fold the dry ingredients into the wet just until you don’t see any flour streaks.

Spread the batter in the prepared pan using a spatula.

Step 4:

Bake about 25 minutes. The center should show moist crumbs if you poke it with a toothpick.

Let the brownies cool in the pan before you add the topping.

Step 5:

Heat heavy cream in a small saucepan until it starts to steam.

Pour the cream over the chocolate chips, wait a minute, then stir until smooth and shiny.

Step 6:

Spread ganache over the cooled brownies in an even layer.

Sprinkle rainbow candy-coated chocolate chips on top, then refrigerate until set.

Tips and Tricks for Making This Recipe

Pan Prep Matters

I always line the pan with parchment and leave extra hanging over, so I can lift the brownies out without cracking the ganache.

Sugar Balance

Both brown and granulated sugar matter here.

The mix gives you chewiness and keeps the crumb soft.

Mixing the Batter

I stop stirring as soon as the flour disappears.

Overmixing makes brownies too tight and takes away that dense bite.

Baking Window

I pull the pan as soon as the center has moist crumbs.

Extra oven time dries these brownies up fast.

Ganache Texture

I let the hot cream sit on the chocolate for a minute.

That rest melts the chips evenly and prevents a grainy ganache.

Clean Cuts

I chill the brownies before slicing, then wipe the knife between cuts so each square has sharp edges and a smooth top.

What to Serve with Cosmic Brownies Recipe

You’ll get the most out of cosmic brownies when you pair them with sides that balance sweetness, temperature, and texture.

I’ve tried a bunch of these combos at home!

Vanilla Ice Cream

Try serving cosmic brownies warm with vanilla ice cream.

The cold creaminess against the dense chocolate? Pretty great.

Cold Milk

You can’t go wrong with a glass of cold milk. I

t cuts the richness and keeps each bite feeling balanced.

Freshly Brewed Coffee

Maybe add a cup of black coffee or lightly sweetened coffee.

The bitterness sharpens the cocoa flavor without making things sweeter.

Homemade Lemonade

It might sound odd, but lemonade actually works.

The acidity cuts through the chocolate and refreshes your palate between bites.

Salted Pretzels

I like to put out a bowl of salted pretzels.

The crunch and salt play off the soft brownie texture nicely.

Espresso Tonic

Give espresso tonic a shot if you like coffee drinks.

The bubbles and bitterness clean things up after each brownie square.

Variations and Substitutions

Fat and Sugar Options

If you want a different richness, swap melted butter with coconut oil.

I do this sometimes for a subtle coconut vibe.

Or replace white sugar with brown sugar for a softer center and those caramel notes.

Egg and Dairy Alternatives

Need an egg-free option? Unsweetened applesauce per egg works.

I’ve baked this way plenty and the structure holds up.

Plant-based butter and dairy-free chocolate are good swaps.

Just watch the bake time; moisture shifts a bit.

Mix-Ins and Toppings

If sprinkles aren’t your thing, top with mini chocolate chips or colored sugar for a different look.

For gluten-free, use a one-to-one gluten-free flour blend.

Let the brownies cool fully before slicing!

How to Store Leftover Cosmic Brownies Recipe

I’ve stored these brownies a lot, and you can keep them fresh depending on how fast you plan to eat them.

Room Temperature

If you’ll eat them within a few days, just pop your brownies in an airtight container at room temp.

Texture and flavor hold up for about three days.

Refrigerator

Want them to last longer? Store brownies in a sealed container in the fridge.

They stay firm and rich for up to a week.

Freezer

For long-term, wrap pieces tightly and freeze in a freezer-safe container.

You’ll get up to three months without much texture change.

Common Mistakes to Avoid

I’ve baked these a lot, and you’ll save yourself some grief by knowing these common slip-ups before you start!

Overbaking the Brownies

Cosmic brownies dry out fast. Check early and pull them when the center still looks a little soft.

Measuring Ingredients Carelessly

Eyeballing flour or cocoa changes the texture.

Measure carefully and use room temperature ingredients for the best results.

Frosting or Cutting Too Soon

If you rush, you’ll probably end up with melted frosting and sloppy edges.

Trust me; letting everything cool all the way really changes the game!