Brace yourself for a truly nostalgic treat: these homemade Cosmic Brownies are fudgy, ultra-chocolatey, topped with rich icing and rainbow sprinkles—just like the iconic lunchbox favorite of your childhood, but so much better. They’re the ultimate answer for any chocolate lover craving a little trip down memory lane (with a cosmic twist, of course)!
Why You’ll Love This Recipe
- Incredible Texture: Every bite of these Cosmic Brownies is perfectly dense and fudge-like—no dry, cakey brownies here!
- Childhood Nostalgia: They taste just like the ones from your lunchbox memories, but made with real chocolate and elevated with homemade goodness.
- Rich, Glossy Icing: The thick chocolate icing melts into the warm brownie base for a melt-in-your-mouth finish topped with fun, colorful sprinkles.
- Make-Ahead Perfect: These brownies actually get even better after chilling, making them a fantastic prep-ahead treat for parties or cravings.
Ingredients You’ll Need
The magic behind Cosmic Brownies is all in the mix of simple pantry staples and a few decadent upgrades. Each ingredient pulls its weight—contributing unbeatable chocolate flavor, gooey chew, or that signature smooth icing. Here’s how they all work together to make your brownies out-of-this-world.
- Dark Chocolate (72%): Real chocolate brings deep, intense flavor and fudgy texture—the key to cosmic-level richness.
- Unsalted Butter: Cold from the fridge is fine! It adds lusciousness to both the brownie and the icing.
- Dutch Process Cocoa Powder: Sifted for smoothness; this intensifies chocolate flavor and gives brownies that signature deep color.
- Large Eggs: Room temperature eggs are important for a glossy, unified batter that bakes up beautifully.
- Caster Sugar & Brown Sugar: The combo of both creates a shiny top, deep flavor, and perfect chewy texture.
- Kosher Salt: Just a touch brings out all the layers of chocolate and balances the sweetness.
- Vanilla Extract or Paste: One small splash brings a bakery-warm note that plays perfectly with the chocolate.
- All-Purpose Flour: Sifted to keep the brownies compact and smooth—no dry spots, just pure chocolate bliss.
- Powdered Sugar & Cocoa (for icing): These form the base of the rich, glossy icing that sets up perfectly on top.
- Boiling Water: Hot water effortlessly melts the butter into the icing, making it silk-smooth and spreadable.
- Rainbow Sprinkles: The best part! Choose your favorites for a true Cosmic Brownies finish—no rules, just fun.
Variations
Cosmic Brownies are endlessly customizable! Don’t be afraid to experiment using your favorite flavors or adapting them for special diets—there’s room to make each batch your own cosmic creation.
- Nutty Cosmic Brownies: Fold in chopped pecans or walnuts for a delightful crunch and extra richness.
- Gluten-Free Version: Swap all-purpose flour with a 1:1 gluten-free baking blend for cosmic results everyone can enjoy.
- Vegan Cosmic Brownies: Use plant-based butter, flax eggs, and dairy-free chocolate for a treat that’s both fudgy and fully plant-powered.
- Extra Cosmic Toppings: Replace rainbow sprinkles with mini M&Ms, chocolate chips, or even edible glitter for a themed party vibe.
How to Make Cosmic Brownies
Step 1: Prepare Your Pan & Oven
Start by lining a 9×13-inch pan with parchment paper, leaving an overhang for easy brownie removal later. Preheat your oven to 350°F (180°C)—getting organized here means your Cosmic Brownies come out clean-edged and picture-perfect every time.
Step 2: Melt the Chocolate and Butter
Combine your chopped dark chocolate and cold butter in a heatproof bowl set over simmering water (or carefully in the microwave), and stir until they melt together into glossy chocolate lava. This sets the stage for ultra-fudgy brownies with real chocolate depth.
Step 3: Add Cocoa for Depth
Sift cocoa over your chocolate-butter mixture and stir again until silky smooth. This extra chocolate punch is what makes Cosmic Brownies extra decadent and gives them their craveable deep color.
Step 4: Whip the Eggs & Sugars
Beat together the eggs, caster sugar, and brown sugar on medium-high speed until the mixture is pale, thick, and falls in ribbons. This step gives your brownies that addictive chew and their classic, shiny top.
Step 5: Bring Everything Together
Pour the cooled chocolate mixture into your whipped eggs and sugars, mixing until just combined. Stir in the salt and vanilla, then fold in the sifted flour gently by hand—careful not to overwork the batter to keep it fudgey.
Step 6: Bake to Just-Set
Spread the batter into your lined pan, tap a few times on the counter to release any air bubbles, then bake for 18–20 minutes. Aim for a set top and edges, with a few moist crumbs sticking to a tester—overbaking will make them less cosmic!
Step 7: Make Icing While Brownies Cool
While the brownies rest, whisk together sifted powdered sugar, cocoa, and salt, then work in softened butter until coated. Add boiling water and mix until the icing is smooth and glossy—it comes together like magic and should be ready when your brownies have just cooled five minutes.
Step 8: Ice, Sprinkle, and Chill
Spoon the lush chocolate icing over your still-warm brownies, smoothing it to every edge. After a minute or two, scatter rainbow sprinkles generously on top. Chill the whole pan in the fridge until totally set—this is the secret to those picture-perfect Cosmic Brownies bars!
Step 9: Slice and Enjoy
When fully chilled, lift the brownies out using the parchment. Use a sharp knife (wipe between slices for the cleanest edges) and serve your Cosmic Brownies for instant smiles. Store leftovers in the fridge, if you happen to have any at all!
Pro Tips for Making Cosmic Brownies
- Shiny Top Secret: Whipping the eggs and sugars really well is what gives Cosmic Brownies that irresistible crackly top—don’t rush this step!
- Smooth Icing Every Time: Always sift your powdered sugar and cocoa for lump-free icing that glides perfectly across the brownies.
- Don’t Overbake: The key to decadent, fudgy brownies is to bake until just set—checking early can mean the difference between cosmic and crumbly.
- Sprinkle Timing: Wait about 1-2 minutes after icing before adding sprinkles; this keeps the colors crisp and stops them from melting into the warm icing!
How to Serve Cosmic Brownies
Garnishes
The classic garnish for Cosmic Brownies is of course a blizzard of micro rainbow sprinkles—bright, cheerful, and fun! Feel free to add a light dusting of extra cocoa powder, a pinch of flaky sea salt, or try themed sprinkles for parties and holidays. Every garnish adds extra flair and personality to your brownies.
Side Dishes
These brownies are rich, so a scoop of vanilla ice cream, a drizzle of warm caramel sauce, or even a bowl of fresh berries makes a delightful pairing. For a truly cosmic touch, serve alongside a tall glass of cold milk or your favorite coffee or hot cocoa for pure comfort.
Creative Ways to Present
Turn your Cosmic Brownies into individual party treats by cutting them into shapes with cookie cutters, or stack squares onto skewers for a fun dessert “kebab.” Layer with ice cream and more sprinkles for a sundae bar at gatherings, or wrap slices in wax paper for a retro-style lunchbox surprise.
Make Ahead and Storage
Storing Leftovers
Keep your Cosmic Brownies in an airtight container in the fridge and they’ll stay moist, fudgey, and totally irresistible for up to five days. Chilling also helps the icing develop that nostalgic, slightly firmed-up texture we all love!
Freezing
Yes, you can freeze Cosmic Brownies! Once chilled and set, wrap them tightly in plastic wrap and slide into a freezer-safe bag or container. They’ll last up to three months and can be thawed in the fridge or at room temperature for a quick treat.
Reheating
If you like your brownies just a touch warm, zap them in the microwave for about 5–10 seconds (any longer and the icing will melt!). They’re especially good slightly warm with a scoop of ice cream, but honestly, they’re cosmic straight from the fridge or freezer too!
FAQs
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Can I make Cosmic Brownies without a mixer?
Absolutely! While using an electric mixer helps whip the eggs and sugars for that signature shiny top, you can beat vigorously by hand with a whisk to achieve similar results. Just make sure to mix until the mixture is pale and increased in volume.
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Why do my Cosmic Brownies sometimes turn out cakey?
If your brownies are cakier than you’d like, it’s usually from overbaking or adding too much flour. Double-check your flour measurement (sift and level) and aim to bake just until a few moist crumbs cling to your tester.
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How do I get really clean, sharp slices?
For those perfect bakery-style slices, chill your Cosmic Brownies thoroughly, then use a very sharp knife, wiping it clean between each cut. This helps preserve the rich icing layer and keeps the sprinkles tidy on top!
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Can I double the recipe for a bigger batch?
Definitely! You can double the recipe and bake in two pans, or use a half-sheet pan (adjust baking time as needed). Just remember—you’ll want to have lots of friends around, or you might just eat them all yourself!
Final Thoughts
If you’re ready for brownie bliss, whip up these Cosmic Brownies and let the nostalgia (and the chocolate) transport you. I can’t wait for you to experience just how magical homemade can be—don’t be surprised if they disappear in a flash!
Print
Cosmic Brownies Recipe
- Prep Time: 20 minutes
- Cook Time: 20 minutes
- Total Time: 40 minutes
- Yield: 16 servings
- Category: Baking
- Method: Oven
Description
These Cosmic Brownies are a fun and colorful twist on classic brownies, topped with a rich chocolate icing and rainbow sprinkles. Perfect for a sweet treat or special occasion!
Ingredients
Brownie
- 200g dark chocolate (72%), coarsely chopped
- 180g unsalted butter, cold
- 15g dutch process cocoa powder, sifted
- 3 large eggs (about 150g), at room temperature
- 200g caster sugar
- 100g light or dark brown sugar
- 2g kosher salt
- 1/2 tsp vanilla extract or vanilla bean paste
- 100g all-purpose flour, sifted
Chocolate Icing
- 250g powdered sugar, sifted
- 25g cocoa powder
- Pinch of salt
- 60g unsalted butter, room temperature
- 40g boiling water
- Rainbow Sprinkles
Instructions
- BROWNIE Preheat the oven and prepare the pan. Melt chocolate and butter, add cocoa powder. Mix eggs, sugars, add chocolate mixture, salt, vanilla, and flour. Bake until set.
- CHOCOLATE ICING Sift sugar, cocoa, salt. Add butter, mix. Pour boiling water, mix until smooth. Spread over brownie, add sprinkles. Chill, slice, and store.
Nutrition
- Serving Size: 1 brownie
- Calories: 290
- Sugar: 25g
- Sodium: 100mg
- Fat: 17g
- Saturated Fat: 10g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 32g
- Fiber: 2g
- Protein: 3g
- Cholesterol: 70mg
