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This Homemade Cosmic Brownie recipe will evoke all those childhood memories of snacking on those little plastic-wrapped store-bought brownies – but these babies are SO much better!
Real, decadent, and satisfying chocolate, without all the crazy artificial ingredients.
When I was a kid in elementary school, anytime I’d bring a sack lunch it was basically the same exact thing every time. I always ate a peanut butter sandwich, I didn’t even like jelly necessarily. There’d usually be some other element in my lunch bag – but I’d ALWAYS request my mom add in a Little Debbie brownie as my special treat.
Before Cosmic Brownies came into existence, it was just the Little Debbie brownies with the nuts on top. I would always pick off all the nuts. In my child mind, nuts shouldn’t be part of any dessert. Gross.
So you can imagine my excitement when I spotted Cosmic Brownies on the shelf at the store. Candy > Nuts any day! I freakin’ loved those Cosmic Brownies. Never did I think I’d grow up to make a copycat cosmic brownie, ha!
I knew I had to make my own version from scratch. I got started making the most fudgy, chewy brownies I could, using everything I learned from my Ultimate Brownie Guide.
These little brownies are ultra-rich and fudgy, almost like candy. I got as close to the texture of the store-bought kind as I possibly could. I hope you love them as much as I do!
How to Make Copycat Cosmic Brownies
What are Cosmic Brownies?
Cosmic Brownies, created by snack company Little Debbie, basically summarize a childhood in the 1990s in each bite. They are chewy with a rich, fudgy frosting that’s dotted with rainbow crunch sprinkles. They come individually wrapped and are super sweet and quite artificial tasting. In creating my copycat version, I opted for a fudgy chocolate ganache topping that delivers a much better burst of chocolate flavor. The store-bought version was one of my favorite childhood treats, so I’ve created a homemade version that’s more suited for an adult palette. No weird chemicals or artificial flavors in these homemade Cosmic Brownies!
Check out the side-by-side below – my homemade version is on the left and the store-bought is on the right:
Where to Find Rainbow Candy-Coated Chocolate Chips?
I used to use Wilton Rainbow Crunch for topping Cosmic Brownies (as seen in the pictures here), but those are increasingly difficult to find. This Baker’s Choice version is available on Amazon, but feel free to use rainbow sprinkles, mini M&Ms, or whatever you like to top these brownies.
Butter vs. Oil in Brownies: Which is Better?
I recently experimented with Butter vs. Oil in brownies to see how the type of fat used affects the final result. The brownies made with butter were fudgier and softer than the oil brownies. There were also shocking differences in the crusts of the two brownie batches! You’ll find these Cosmic Brownies call for all butter to provide the best flavor and melt-in-your-mouth texture.
Check out my Butter vs. Oil in Baking article for a full breakdown on each of these fats and how they affect tenderness, flavor, and texture in baked goods (and not just brownies).
Do I Have to Use Cornstarch + Corn Syrup?
There is a small amount of both cornstarch and corn syrup in this recipe to help make the brownies super chewy and fudgy. Feel free to omit the corn syrup or use golden syrup if you prefer, but note that your brownies just won’t quite have that same Cosmic texture. Don’t skip the cornstarch – learn why here.
Extra Egg Yolk = Fudgy & Chewy!
You’ll notice in most of my brownie recipes I add an extra egg yolk. This adds fat and protein which translates to rich, fudgy, and chewy brownies.
How to Avoid Dry, Crumbly Cosmic Brownies
To get moist, fudgy, and chewy Cosmic Brownies, you want to be extra careful to measure your dry ingredients properly. It’s super easy to accidentally add too much flour and cocoa powder – unless you use a digital kitchen scale to ensure 100% accuracy. If you don’t have a scale, use the spoon and level method for both the flour and cocoa powder to ensure accuracy, and avoid dry, hard, cakey, or crumbly brownies. You can learn more about how to measure properly here.
The Best Brownie Baking Pan
- I highly recommend using a light-colored metal baking pan. This is my favorite baking pan for brownies, blondies, cheesecake bars, cookie bars, and more.
- Avoid using dark-colored metal pans; the darker the color, the more likely you are to burn the edges or have dry edges.
- Glass or ceramic baking pans will take LONGER to bake these brownies, and the texture may become dense and gummy. Learn more in my Glass vs. Metal Baking Pans article.
How to Cut Cosmic Brownies Perfectly
If you want to get perfectly clean, neat, and even brownie slices, check out my How to Cut Brownies Cleanly in 5 Steps article. Don’t worry – even if you don’t follow all these tips, your brownies will taste just as delicious.
How to Store Cosmic Brownies
Frosted, sliced Cosmic Brownies can be stored in an airtight container for 3 days at room temperature or for 1 week in the fridge. Cosmic Brownies are best served chilled, for maximum fudginess.
More Brownie Recipes
- Best Easy Brownies (1 bowl, no mixer, less than 1 hour)
- Best Chewy Brownies (perfect if you love the texture of box mix!)
- Nutella Brownies (one of my top posts on Instagram!)
More Copycat Recipes
- Brown Butter Rice Crispy Treats
- Homemade Fudge Rounds
- Strawberry Pop Tarts
- Homemade Oreos
- Homemade Oatmeal Cream Pies
For the brownies:
- 10 tablespoons (142 grams) unsalted butter
- 1 cup (200 grams) granulated sugar
- 1/3 cup (67 grams) packed light brown sugar
- 3/4 cup plus 2 tablespoons (88 grams) unsweetened cocoa powder, sifted
- 1/2 teaspoon vanilla extract
- 2 large eggs plus 1 egg yolk
- 1 tablespoon corn syrup
- 2/3 cup (85 grams) all-purpose flour
- 1 tablespoon cornstarch
- 1/4 teaspoon salt
For the frosting:
- 1/2 cup heavy cream
- 1 1/2 cups (255 grams) semisweet chocolate chips
Rainbow Candy-Coated Chocolate Chips, or mini M&M’s, sprinkles, or other candy, for topping
Make the brownies:
- Preheat the oven to 350°F. Line an 8-by-8-inch metal baking pan with parchment or foil and spray with cooking spray.
- In a large microwave-safe bowl, melt the butter for about 90 seconds on high power. Stir in the granulated sugar, brown sugar, and cocoa powder. If still very hot, let cool slightly before adding in the vanilla, eggs, egg yolk, and corn syrup. Stir until very well combined. Add in the flour, cornstarch, and salt and stir until just combined. Batter will be thick. Pour into the prepared pan and bake for 25 minutes. Let cool completely in the pan.
Make the frosting:
- Place the cream in a small microwave-safe bowl and microwave on high for 1 minute. Add in the chocolate chips. Let stand for 3 minutes before stirring until smooth. Pour over the cooled brownies and smooth evenly. Sprinkle with the Rainbow Candy-Coated Chocolate Chips. Refrigerate for 1 to 2 hours, or until the frosting is set, before cutting.
- Brownies can be stored in an airtight container for 3 days at room temperature and for 1 week in the fridge. Brownies are best served chilled.
Where to Find Rainbow Candy-Coated Chocolate Chips?I used to use Wilton Rainbow Crunch for topping Cosmic Brownies, but those are increasingly difficult to find. This Baker’s Choice version is available on Amazon, but feel free to use rainbow sprinkles, mini M&Ms, or whatever you like to top these brownies.
This recipe was originally published in 2014 and has been updated with recipe improvements and new photos. Photos by Ashley McLaughlin.
April Baking Challenge
This recipe was the selection for the April 2020 baking challenge! See all the entries submitted below. Check out the current monthly challenge here.