Fudgy Homemade Cosmic Brownies (copycat)
These homemade copycat Cosmic Brownies are super fudgy and rich! They are topped with a smooth chocolate frosting and the classic rainbow crunch sprinkles. They are just like the packaged brownies you love but even better because they are made fresh!

These cosmic brownies are so much fun to make- I loved them so much that I turned this classic dessert into cosmic brownie cookies too.
The original Cosmic Brownies are made from Little Debbie’s but sometimes you don’t want to go to the store and buy them. Thats why we are making them here today!
As a professional baker I love figuring out how to make classic, sometimes nostalgic recipes on my own. It’s a fun challenge and today I figured it out!
What makes these so good is a thick layer of dense, and chocolatey brownie that’s topped with a rich chocolate brownie frosting and sprinkled with rainbow chips. The brownie layer is so good that I actually used it in my chocolate mousse cake as the bottom layer.
They are the type of brownies where when you take a bite- your teeth leave streaks in it. Like that good.
You can leave them at room temperature or eat them straight from the fridge, they are *chefs kiss* either way.
Ingredients
Cosmic brownies have special sprinkles called Rainbow Chip Sprinkles (Brownie Crunch) made by Wilton, which are really hard to find because they don’t sell them anymore on the Wilton site.
BUT- You can find them in a Wilton sprinkle mix (not a stand alone) which is where I found these ones. Or from Walmart or from Nuts.com.
If you can’t find them, you can also use mini m&m’s or any kind of sprinkles. But to get close to exact copycat cosmic brownies you need the rainbow chip ones.
Hot tip– Immediately after frosting the brownies, top them with sprinkles because the frosting sets up fast!
How to make them
How to cut brownies cleanly
- Refrigerate the brownies for 2 hours. Brownies cut more easily when they are cold.
- Dip a large chefs knife in warm water for 5 seconds.
- Wipe off the knife and cut the brownies in a straight line wiping off the knife after each cut.
- Start in the middle and then cut into 1/3rds, then rotate and repeat.
Fudgy Homemade Cosmic Brownies (copycat)
Ingredients
- 1/2 cup butter, unsalted
- 6 oz semi sweet chocolate, about a heaping 1 cup
- 1 cup granulated sugar
- 3 eggs, large
- 1 tsp vanilla extract
- 2/3 cup all purpose flour
- 3 tbsp unsweetened cocoa powder
- 1/2 tsp kosher salt
- 1 batch chocolate brownie frosting, see instructions below
- Rainbow Chip Sprinkles
Instructions
- Preheat the oven to 350° F and line a 8×8 pan with parchment paper or spray with baking spray.
- In a medium size microwavable safe bowl, melt the 1/2 cup butter and 6 oz chocolate together, 30 seconds at a time until fully melted.
- Add in the 1 cup sugar, 3 eggs, and 1 tsp vanilla. Mix on low to medium speed with a hand mixer or whisk by hand.
- Add in the 2/3rd cup flour, 3 tbsp cocoa, and 1/2 tsp salt. Mix until combined.
- Pour the batter into the prepared pan and bake for 28-30 mins until the edges of the pan start to break away. Cool.
- For the frosting make this easy brownie frosting and top with rainbow crunch sprinkles or mini m&ms immediately after, or the frosting will harden.