I Tried This Homemade Recipe for Cosmic Brownies — Here’s How It Measured Up to the O.G. Nostalgic Treat

Little Debbie’s Cosmic Brownies will always hold a special place in my heart. When I was a kid, I couldn’t resist the allure of the brand’s rainbow chip-topped, sweet, fudgy brownies. (And today Little Debbie is still keeping things interesting by coming out with ice cream flavors inspired by those childhood favorite snacks.) So when I came across this recipe for Cosmic Brownies by @designeatrepeat on TikTok, I knew I had to try this homemade version.

Since I love a fun copycat recipe, I wasted no time jumping on this one. I grabbed the short list of pantry ingredients required for this recipe (including some very fun sprinkles!) and got to baking. Extremely excited to recreate one of my favorite childhood desserts, I just knew this one was going to be a hit with my tastebuds.

Get the recipe: Homemade Cosmic Brownies

This recipe is basically made the same way you’d make other homemade brownie recipes. It’s fairly simple, requiring mostly pantry ingredients (aside from the candy-coated chocolate pieces), but does take a decent amount of time. From making the batter to baking the brownies — and making and cooling the ganache — it takes over an hour from start to finish (including inactive time).

For the brownies, start by melting unsalted butter, and both granulated and brown sugar in the microwave then stir until smooth. Then stir in the whole eggs, egg yolk, vanilla, salt, baking soda, and cornstarch. The addition of the egg yolk helps to make the brownies nice and chewy while the cornstarch helps keep them moist and fudgy. Once that’s all mixed together, add in the cocoa powder and flour and mix until just combined. Last, stir in the vegetable oil. Bake the brownies until the center looks set.

As the brownies cool, you’ll make the chocolate ganache. Place chocolate chips and butter in a bowl and heat whole milk in the microwave or on the stovetop. Pour the hot milk over the chocolate chips and butter, wait a few minutes, then whisk until it’s smooth and creamy. Once the brownies are completely cool, and the ganache has cooled for at least 30 minutes, spread the ganache over the brownies and top with the rainbow chip sprinkles. Place the brownies in the fridge for about an hour to harden, then just slice and enjoy!

As I mentioned above, this recipe for Homemade Cosmic Brownies is a bit of a process, but let me tell you that it’s worth it! All of the steps are easy to follow, and described very well in the recipe instructions. Before making this recipe, I bought a box of Cosmic Brownies for old time’s sake, and for *research* purposes. I’d be lying if I told you that the homemade version has that same nostalgic flavor of Little Debbie’s Cosmic Brownies, but honestly I’d choose the homemade ones over store-bought any day.

The homemade version is intensely chewy and fudgy, which is the best of both worlds when it comes to brownies, in my opinion. The ganache is the perfect replacement for the icing on the store-bought Cosmic Brownies, and is much more creamy and fudgy. This recipe is basically Cosmic Brownies for adults! I know I’ll be coming back to this one time and time again when I’m craving those boxed snack cakes, but want a more adult version. And I know kids would come running for them, too.

1. Don’t over-mix the batter. You want these brownies to stay both chewy and fudgy, and over-mixing will ruin that nice balance. I’d suggest mixing the flour in until a few streaks remain so when you add the vegetable oil last, you don’t over-mix the batter. Also, mixing by hand the whole time can help give you more control over the batter — versus using an electric or stand mixer — and help you avoid over-mixing.
2. Don’t over-bake. I also think I could have baked my brownies slightly less. The recipe suggests baking for 24 to 26 minutes, but I’d check at around 20 minutes and go from there.
3. Make sure the milk is hot enough before adding it to the butter and chocolate for the ganache. I had a bit of trouble when I was mixing the ganache. The chocolate chips didn’t melt as quickly as they were supposed to, and it took a lot longer for the ganache to become smooth. I think next time, I’ll heat the milk just a few seconds longer in the microwave.
4. Make the ganache when the brownies are almost done cooling. The ganache has to cool for about 30 minutes before spreading onto the brownies, and I found the timing was perfect by making it when the brownies were almost done cooling.