When I was growing up Little Debbie brownies were just regular frosted brownies with walnuts on the top. Still definitely a yummy childhood lunchbox treat, but it wasn’t until 1999 when Little Debbie introduced their cosmic brownies with the rainbow colored chocolate pieces on top that they seemed to gain a cult following! While some folks might guess that the name comes from their colorful chips giving these galaxy brownies an intergalactic look, the moniker was actually in tribute to the popular cosmic bowling craze of the 90’s! Bowling in the dark with black lights making everything glow neon is something I definitely grew up with, and it’s what actually inspired the look of these treats! Other Little Debbie favorites included oatmeal cream pies, star crunch, zebra cakes, Christmas tree cakes, and honey buns. Looking for fun, colorful dessert ideas? Our Homemade Funfetti Cake and Homemade Rainbow Chip Frosting are reader favorites that you might also enjoy!
Why this Recipe Works
Homemade cosmic brownies have a really dense, fudgy brownie layer with a creamy but firm fudgy icing on top, just like the originals. Most other homemade cosmic brownies recipes use a chocolate ganache on top. But the actual cosmic brownies have a chocolate icing that firms up into a fudgy, solid layer. It’s basically the same icing I use when I make Bumpy Cake, so I just scaled that back and adjusted a few things to make it work for these brownies. The rainbow coated chocolate pieces add a fun pop of color but also an interesting texture to the top of these brownies.
Ingredient Notes
Rainbow coated chocolate chips: I have seen these at many grocery stores (the ones I used are Wilton brand called “rainbow chip crunch” and are by all the other sprinkles) but they are also easy to find at craft stores like Joann’s, Michael’s, or Hobby Lobby. Or you can always just order them online. Cocoa powder: I made these with good old Hershey’s unsweetened cocoa powder. Sugar: The combination of granulated sugar and brown sugar gives a better depth of flavor to the cosmic brownies than using just granulated sugar.
How to Make This Recipe
Start by beating the melted butter with both types of sugar in a large bowl. This can also be done by hand. Add the eggs, egg yolk, and vanilla, then beat again. Stir in the flour, cocoa powder, cornstarch, and salt by hand just until everything is combined. Pour and spread into the corners of a 9×13-inch pan lined with a parchment paper sling for easy removal once the brownies have cooled. Bake for 18-22 minutes, just until the brownies are done and a toothpick inserted into them comes out with just a few crumbs on it. You don’t want to overbake or the brownies will be dry. Cool completely before topping with the fudge frosting. To make the fudge frosting, start by combining the sugar, milk, butter, and cocoa powder in a medium saucepan over medium heat. Cook, stirring frequently until the butter has melted and the mixture comes to a boil. Boil for 3 minutes, then remove from the heat and beat in the powdered sugar and vanilla until smooth. While the frosting is still hot, pour it over the cooled brownies and tilt the pan to spread the frosting into the corners and create an even layer of fudge icing on top. Sprinkle with the rainbow coated chips while the frosting is still soft so they can sink in slightly since the fudge frosting sets up fairly quickly. Let your homemade cosmic brownies sit uncovered until the frosting has cooled completely and had a chance to set up before lifting them out of the pan and slicing into rectangles or squares. If you want clean edges when slicing these homemade cosmic brownies, I recommend chilling them for a bit first so they are cold. If I’m taking pics and wanting really clean slices, I will even go so far as to rinse the knife under hot water and wipe it with paper towels between each slice. Also, try to do one quick slice, rather than dragging the knife through the brownies, which can cause them to tear and stick to the knife.
Recipe Tips
Storage: You can keep these brownies on the counter in an airtight container for 4-5 days or in the fridge for about a week. Freezing: These freeze great for 2-3 months. I recommend slicing and separating the brownies, then freezing them on a baking sheet for an hour before transferring to an airtight freezer-safe container for longer term storage. Thaw on the counter for a couple of hours before enjoying. Pan size: You could make these in a smaller pan like a 9×9 for thicker cosmic brownies, but you will need to adjust the baking time to be a little longer, probably more like 26-30 minutes.
More Brownie Recipes
Ultimate Peanut Butter Swirl Brownies Cream Cheese Brownies German Chocolate Brownies Slutty Brownies [Brownie Oreo Chocolate Chip Cookie Bars]
The BEST Homemade Brownies
Frosted Brownies
Gooey Swirled Nutella Brownies
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