Homemade Cosmic Brownie Recipe (2024)

Published on February 1, 2024 | Updated on February 1, 2024 by Melissa

This homemade Cosmic Brownie recipe is a copycat version of Little Debbie’s famous treat. A chewy decadent brownie topped with a rich chocolate ganache and rainbow chips. If you liked the classic rainbow sprinkle brownies, you’ll love this upgraded version even more!

My parents were never big on packaged desserts. I really don’t think I’ve had a Twinkie. But there is something so nostalgic about any of the snacks that come in those recognizable boxes.

I was always so intrigued by the little rainbow chips on Cosmic Brownies. They’re still so fun.

I can pretty confidently say that brownies are my favorite dessert. You’ve seen me make coconut oil brownies, better than box mix brownies, and Halloween cream cheese swirl brownies…just to name a few. So I can safely safe I am a pretty decent brownie critic.

When, as an adult, I had my first Cosmic Brownie, I was so disappointed. They taste a bit…cardboardish? This homemade version is 100% better, but still has the same nostalgic vibes.

They are nut-free and safe for school lunches and bake sales, they make a great afternoon snack with a cold glass of milk and of course perfect for an after-dinner dessert.

Things you’ll need

• 9×13 Baking Dish – I love that this has a lid for storing.
• Mixing Bowls – I love the grippy bottoms on these.
• Offset Spatula – Helps to spread the ganache (or any frosting).
• Rainbow Chips – In case you can’t find them in the store.

Cosmic Brownie Ingredients

Below is a list of the ingredients you’ll need to gather to make this recipe.Scroll all the way down for the full recipe card.

• Sugars – You’ll need a mix of both granulated white sugar and brown sugar.
• Vanilla Extract – Pure vanilla extract (not imitation) for the best flavor. I buy it in bulk at Costco or Sam’s Club.
• Salt – To balance the sweet.
• Eggs – You’ll add two full eggs and two egg yolks. The extra egg yolk makes for an even richer brownie.
• Butter – Salted or unsalted. I personally usually use salted.
• Chocolate chips – I like to use Ghirardelli 60% baking chips but semi-sweet chocolate chips work fine if that’s what you prefer.
• Rainbow Candies – You can find these on Amazon or at Hobby Lobby. Mini M&M candies will also work.
• Vegetable Oil – The combo of melted butter and some oil makes for amazing texture.
• Flour – I’ve only tested with all purpose flour.
• Cocoa Powder – Unsweetened cocoa powder.
• Heavy Cream – To make the chocolate ganache frosting, you’ll need heavy cream. Whole milk will also work, but you’ll need to add some butter. Or, I have a thinner frosting option listed in the recipe card, if you prefer.

How to make Cosmic Brownies

This section shows you how to make this recipe, with process photos showing the steps to help you visualize it. For full instructions, including amounts and temperatures, see therecipe card below.

1. STEP ONE: To a large mixing bowl, whisk together the sugars, vanilla, salt, eggs and yolks.
   
2. STEP TWO: Add the butter and chocolate chips to microwave safe bowl and heat in 30 second intervals, stirring between each, until melted and smooth. Whisk in the vegetable oil.
   
3. STEP THREE: Pour the cooled chocolate mixture into the sugar mixture and stir until combined. Then gently fold in the flour and cocoa until there are no traces of powder.

4. STEP FOUR: Pour the brownie batter into a 9×13 baking dish that has been lined with parchment paper and bake in a 350°F preheated oven for 30 minutes or until a toothpick inserted in the middle comes out clean.
   
5. STEP FIVE: To make the ganache, pour the heavy cream into a medium microwave safe bowl and heat for 1 minute. Pour the chocolate chips in and let them sit for 2-3 minutes. After sitting, stir until melted and smooth.
6. STEP SIX: Pour the ganache onto the cooled brownies and spread into an even layer. Sprinkle on the rainbow chips and let set. Once set, slice and serve!

Let cool completely before slicing.

Why are they called Cosmic Brownies?

The original Little Debbie’s snack version of these cosmic brownies were developed in the 60’s however there doesn’t seem to be much written on why they are called what they’re called.

One can only assume it’s because the colorful chocolate chips atop the dark chocolate brownie mimics the galaxy!

How to store them

With the cream based chocolate ganache topping, I prefer to store them covered in the fridge. They are best eaten within the first couple of days, but they’ll last up to 4 days.

They won’t last that long. Promise.

Can I freeze them?

Yes, wrap the brownies individually and place in a freezer bag. They can be frozen for up to 3 months.

Move them to the fridge to thaw when you’re ready to enjoy them.

Where do I find rainbow chips?

Rainbow chips are unique in that they are chocolate chips that are candy-coated which gives them those fun colors!

They are not as easy to find as regular chocolate chips but Walmart and Hobby Lobby carries them.

Any bulk food/candy store should have them as well but if you are really having a hard time, you can always order online.

While you have them, make a Cosmic Brownie Pie, Cosmic Brownie Cookies and Cosmic Brownie Hot Chocolate Bombs while you’re at it.

Need more homemade Little Debbie treats? Try these:

• Oatmeal Cream Pies
• Zebra Cakes
• Fudge Rounds

Click here to view my entire collection of brownie recipes.

Originally published July 26, 2020; photos and recipe updated February 1, 2024.