I have to admit something. One of my favorite store bought snacks is a Cosmic Brownie! The dense chocolate brownie with just the right amount of chocolate frosting and rainbow chips that you unwrap from those plastic bags are magic. Maybe it is because they remind me of my childhood or maybe it is because brownies in any form are irresistible. Either way creating a cookie version of this boxed treat has been amazing in every way. Easy Cosmic Brownie Cookies start with a brownie mix and end with the same rainbow chips you know and love. You need these cookies!
Do you love brownie cookies? Try these Loaded Brownie Pretzel Cookies Recipe!
Cosmic Brownie Cookies
I started these delicious Cosmic Brownie Cookies with a brownie mix. Being able to turn a boxed brownie mix into a cookie is such a time saving way to bake.
A simple frosting and rainbow chips from the sprinkle section of the grocery store are the only other elements needed to complete these amazing cookies.
They come together quickly and can be served warm or chilled, depending on your personal preference. The only thing I must demand is that you don’t wait and bake a batch today!
Ingredients Needed
Brownie Cookie
- Brownie Mix-The perfect starting point for a soft and delicious brownie cookie. See this Double Dark Chocolate Chip Cookie recipe for another fun option.
- Flour-Adding a bit of flour to the dry brownie mix will give a cookie a bit more body.
- Eggs-An ingredient added to most baking recipes to help bind the ingredients and give the product a nice texture.
- Vegetable Oil-Added to give the cookies a wonderful moist crumb.
Chocolate Glaze/Frosting
- Butter-A delicious base for this chocolate frosting.
- Powdered Sugar-The perfect sugar for any kind of frosting because of its soft texture.
- Cocoa Powder-Added to give the frosting a wonderful chocolate flavor.
- Heavy Cream-Added to the frosting to help thin it and give it a wonderful flavor.
- Vanilla Extract-An ingredient added to add even more flavor!
How to make Cosmic Brownie Cookies with a Brownie Mix Cookie
- To get a little extra structure to the cookie and be sure that they turned out soft and chewy, I added 3 tablespoons of flour to the brownie mix. Use a whisk to mix them together and take out any lumps. Mix the dough by hand {or with a hand held mixer} until everything is well combined {the dough will be pretty thick}.
- Use a 1/4 measuring cup to measure out cookie dough mounds. This will ensure that all of the cookies are the same size and they bake up nicely. Place 6 at a time onto a silicone mat {or parchment} covered baking sheet.
- Bake for 11-13 minutes or until the edges are set. The middle will still be a little soft but that’s alright. Remove them from the oven and let them cool on the baking sheet. The most important thing to remember is not to over-bake the cookies.
- These sweet little rainbow chips can be found by the sprinkles in the cake section of the grocery store.
- The frosting is made with butter, cocoa, powdered sugar, heavy cream and vanilla. I used a hand held mixer to get everything incorporated well and smooth. Once the cookies are just cooled, begin to take a teaspoon {or so} of the frosting and spread it on each cookie. Then liberally sprinkle the top with the rainbow chips.
- The very best part is the first bite! Look at the center of that baby. Just like a perfect brownie but in a cookie form!
Tips & Tricks
- Use a 1/4 measuring cup to measure out the cookie dough. This will ensure that all of the cookies are the same size and that they will bake evenly. This will also give you nice large cookies.
- Don’t over bake the cookies. Pull them from the oven once the sides are set and the middle is cooked but not completely done. If you bake the cookies too long they will not be soft like you expect from a brownie cookie.
- Allow the cookies to cool on the baking sheet. The residual heat from the baking sheet will continue to slightly bake the cookies and set them up perfectly.
- Add the frosting to the cookies once they are slightly cooled but not all of the way. In order to get the glossy frosting that almost melts into the cookie, the cookie will need to be slightly warm.
- Sprinkle with rainbow sprinkles while the frosting is still wet. If you wait too long the frosting will set up and the sprinkles will not stick.
Frequently Asked Questions:
How to Store Cosmic Brownie Cookies?
The best way to store Cosmic Brownie Cookies is in an airtight container either at room temperature or in the refrigerator. This will depend on whether you prefer eating them chilled or at room temp.
The cookies will last a day or two longer in the refrigerator.
How to Serve?
How you serve the Easy Cosmic Brownie Cookies is a personal preference. I prefer mine warm right after they have been frosting but my family would rather they chill in the refrigerator for an hour or two.
Are they like Crumbl Cosmic Brownie Cookies?
Yes, they are a lot like the Crumbl version of Cosmic Brownie Cookies. This recipe is a very large cookie, covered in chocolate frosting and topped with rainbow chips.
Can I freeze Cosmic Brownie Cookies?
These brownie cookies can be frozen for up to 3 months as long as they have been stored in an airtight container.
Can I bake smaller cookies?
Absolutely! Use a medium cookie scoop and bake for 9-11 minutes. Frost and store as the recipe directs. You should get between 20-22 smaller cookies.
Where do I find rainbow chip sprinkles?
They can be found in the baking section of the grocery store with the other sprinkles. You can also order them off of Amazon here.
How do I get perfectly round cookies?
There are a few ways to ensure that you get nice round cookies. First of all, either use a cookie scoop or roll the cookie dough in your hand and create a round cookie mound.
You can also use a round cookie cutter that is a bit larger than the baked cookie. While the cookies are still warm, place the cookie cutter over the cookies and move the cutter in a circular motion. This will help to remove any imperfections and give you a nice round cookie.
Do you love cookies? Try these easy recipes!!
- Easy Strawberry Crunch Cookies
- Texas Sheet Cake Cookies
- Easy Boston Cream Pie Cookie Bites Recipe
- Kentucky Butter Cake Cookies Recipe
- Easy Raspberry Crumble Cookies
- Oreo Sheet Cake Cookies Recipe
Easy Cosmic Brownie Cookies
Ingredients
Brownie Cookie
- 1 box dry brownie mix
- 3 tbsp flour
- 2 eggs
- 1/4 cup vegetable oil
Chocolate Frosting
- 1/2 cup butter {softened}
- 2 cups powdered sugar
- 1/2 cup cocoa powder
- 1/3 cup heavy cream
- 1/2 tsp vanilla
Instructions
Cookies
- Preheat oven to 350°. Combine the brownie mix and flour in a bowl and whisk until the ingredients are incorporated and any lumps are removed. In a separate bowl combine the eggs and oil, whisk until the ingredients are combined and add it to the dry ingredients. Using a wooden spoon {or hand held mixer}, stir the ingredients together until everything is well combined and thick. Use a ¼ measuring cup to measure cookie dough mounds. Form the dough into round discs. Bake 6 at a time for 11-13 minutes or until the edges are set, they will appear to be a little under cooked but that is alright. Remove cookies from the oven and let them cool on the cookie sheet.
Frosting
- Add the frosting ingredients to a large bowl and combine with an electric mixer {I used a hand held mixer} until the frosting is totally combined and smooth. Add additional heavy cream if the frosting is too thick.
Assembly
- Once the cookies are cooled {or almost completely} begin frosting the top of each cookie with a teaspoon of frosting and sprinkle with mini chips.
- Store leftovers in an airtight container at room temperature for 3 days or the refrigerator for 4-5 days.
Notes
- Don't over bake the cookies. Pull them from the oven once the sides are set and the middle is cooked but not completely done. If you bake the cookies too long, the brownie mix cookies will be dry instead of fudgy.
- Allow the baked cookies to cool on the baking sheet. The residual heat from the baking sheet will continue to slightly bake the cookies and set them up perfectly.
- Add the frosting to the cookies once they are slightly cooled but not all of the way. In order to get the glossy frosting that almost melts into the cookie, the cookie will need to be slightly warm.
- Sprinkle with rainbow sprinkles while the frosting is still wet. If you wait too long the frosting will set up and the sprinkles will not stick.
Nutrition

Alex says
I tried the recipe and it was really good. The recipe is amazingly good.
June says
I am so glad that you enjoyed it. 🙂