The BEST soft, fudgy, and chewy brownie cookies inspired by Little Debbie's cosmic brownies! Enjoy chilled for the perfectly fudgy & dense texture.

chocolate cosmic brownie cookies with rainbow sprinkles on metal cooling rack

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Why I Love These Cosmic Brownie Cookies

Super Fudgy & Dense: just like my copycat cosmic brownies, these cookies have a thick, dense, and super fudgy texture. The use of dark cocoa powder & the addition of a tiny bit of corn syrup helps give it this iconic chewy texture.
Easy to make: these double fudge cookies are one of those cookies that look fancy but are actually easy to whip up! The ganache comes together quickly using the microwave (no stovetop needed!). No need to run to Crumbl next time you're craving one of these bad boys.
A crowd favorite: Whether you're making them giant or scooping them into smaller, bite-sized cookies for holiday platters (see how I make them Christmas-themed below!), these are one of those cookies that everyone loves.

cosmic brownie cookie fudgy dense texture

Ingredient Notes

Cocoa Powder: I use and recommend Hershey's Special Dark Cocoa powder to give them a moist, rich flavor. You can substitute for regular unsweetened cocoa powder, just note that your cookies will have a puffier texture and won't have the iconic brownie taste.
Rainbow chip sprinkles: You can find these at Michaels, Amazon, or one of my favorite budget-hacks is to get a box of Pillsbury Funfetti brownie mix (at most grocery stores!) and use the packet inside. You can then just keep the brownie mix for another time.
Light corn syrup: We're using a small amount of corn syrup to create a chewy, dense, fudgy cookie. Omitting it will not result in the ideal texture, so I highly recommend using it (ps. light corn syrup is not the same as high fructose corn syrup!). You can find this in the baking aisle (Karo or generic brand works). If you can't find it where you live, you can try using thick honey or light molasses to achieve a similar texture (it won't be exact). Or you can use 1 tablespoon of milk but keep note that the cookies will likely end up puffier and won't have the same chewy, dense, fudgy texture.
Heavy cream: In order to get a thick chocolate ganache that "hardens", you'll want to use heavy cream (also known as "heavy whipping cream" at grocery stores).
Chocolate chips: I use semi-sweet chocolate chips but if you want a more subtle chocolate flavor, you can use milk chocolate chips.

container of hershey's special dark cocoa powder

Where to buy the sprinkles?

I get my rainbow chip sprinkles on Amazon! It's a big, bulk-sized bag that will last you for a while! It also comes with a resealable bag for easy storing.

And! You can use them on my other cosmic recipes: Homemade Cosmic Brownies or even just use as an ice cream topping on my No Churn Chocolate Ice Cream!

Buy On Amazon

How to Make Cosmic Brownie Cookies

This is just an overview showing step-by-step photos, jump to full recipe card with exact instructions.

Step 1: Make Cookie Dough

In a large bowl, use an electric mixer to mix together cookie dough. Dough should be thick and similar to a play-doh consistency, as shown below.

Preheat oven to 350°F.
In a large bowl, use an electric mixer on medium-high speed to cream softened unsalted butter (½ cup, 1 stick), light brown sugar(½ cup), and granulated sugar (¼ cup) for 2 minutes until light and fluffy.
Add the egg (1 large), vanilla extract (1 teaspoon), and light corn syrup (2 tablespoons) and mix on low speed until combined. Scrape down the sides of the bowl so everything can combine.
Add in baking soda (¼ teaspoon) and salt (¼ teaspoon) and mix for another 5-10 seconds until combined.
Lastly, add dark cocoa powder (½ cup) and all-purpose flour (1 ¼ cups) and mix on medium until combined.

Tip: Using softened butter is important here! If your butter is straight from the fridge, microwave for 10 seconds to slightly soften.

hand holding chocolate cosmic brownie cookie dough

Step 2: Scoop, Flatten, Bake

Scoop dough into ¼ cup (4 tablespoons) sized scoops (I use this stainless steel cookie scoop!), roll into balls, then gently flatten each dough ball into a ½" thick disc; this will help them spread instead of be puffy. Bake at 350°F for 11-12 minutes, then allow cookies to fully cool before topping.

Tip: Baking on a parchment-lined, light-colored metal pan will allow your cookies to bake evenly without overbrowning. This is the trick to soft, chewy cookies!

baked, unfrosted cosmic brownie cookies on pan

Step 3: Decorate

After the cookies are cooled, spoon 1 tablespoon of chocolate ganache on each cookie and top with rainbow chip sprinkles.

Jump to full recipe card with exact instructions to make the ganache.

chocolate ganache in glass bowl with fork

Step 4: Refrigerate & Enjoy!

Refrigerate the frosted cookies to help the ganache set. Chilling will also help them become even better & fudgier! You can also keep them at room temperature for up to 2 days, if desired.

Tips & Variations

Make it holiday themed! Pick out the red, pink, and green rainbow chip sprinkles (shown below!) to make them Christmas-themed!
Top with mini m&m's or sprinkles: Don't have rainbow chip sprinkles? You can also top with mini m&m's or any sprinkles of your choice!
Have extra ganache? If you end up with a little extra chocolate ganache, stick in a ziploc bag in the freezer and then add to hot cocoa!

christmas cosmic brownie cookies with pink, red, green sprinkles

Frequently Asked Questions:

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Fudgy Cosmic Brownie Cookies (TikTok Viral!)

The BEST soft, fudgy, and chewy brownie cookies inspired by Little Debbie's cosmic brownies! Enjoy chilled for the perfectly fudgy & dense texture.

4.97 from 539 votes

Print Rate

Total Time: 1

Servings: 8 large cookies

By: Melissa Rose

Ingredients

½ cup unsalted butter softened
½ cup light brown sugar
¼ cup granulated sugar
1 large egg
1 teaspoon vanilla extract
2 tablespoons light corn syrup Fun fact: this is not the same thing as high fructose corn syrup!
¼ teaspoon baking soda
¼ teaspoon salt
½ cup dark cocoa powder I use Hershey's Special Dark
1 ¼ cup all-purpose flour

Toppings:

¾ cup semi-sweet chocolate chips
¼ cup heavy cream
rainbow chip sprinkles

Before you begin! If you make this, will you do me a huge favor and leave a review and rating letting me know how you liked this recipe? This helps my small business thrive so I can continue providing free recipes and high-quality content for you.

Instructions

Preheat oven to 350°F.
In a large bowl, use an electric mixer on medium-high speed to cream softened unsalted butter (½ cup, 1 stick), light brown sugar (½ cup), and granulated sugar (¼ cup) for 2 minutes until light and fluffy.
Add the egg (1 large), vanilla extract (1 teaspoon), and light corn syrup (2 tablespoons) and mix on low speed until combined. Scrape down the sides of the bowl so everything can combine.
Add in baking soda (¼ teaspoon) and salt (¼ teaspoon) and mix for another 5-10 seconds until combined.
Lastly, add dark cocoa powder (½ cup) and all-purpose flour (1 ¼ cups) and mix on medium until combined.
Scoop dough into ¼ cup (4 tablespoons) sized scoops (I use this stainless steel cookie scoop!), roll into balls, then gently flatten each dough ball into a ½" thick disc; this will help them spread instead of be puffy.
Bake at 350°F for 11-12 minutes. Do not overbake. The centers may look a tiny bit wet but will continue to bake on the hot pan, allowing them to firm up without overbaking.
Allow to fully cool before decorating.

To Make Chocoalte Ganache:

In a medium-sized, heat-safe bowl (cereal bowl sized), place semi-sweet chocolate chips (¾ cup).
In a separate medium-sized bowl or large liquid measuring cup, heat heavy cream (¼ cup) in the microwave for 30-45 seconds, or until it begins to bubble (it’s important that your measuring cup or bowl is at least 4x taller than the milk line, as it will expand when it’s heating and can easily overflow). You can also heat this on the stove; remove it once it begins to steam.
Use a hot pad to carefully remove milk from the microwave and pour over the chocolate chips (do not stir yet!). Use a fork to press down the chips so that they're fully covered with the cream.
Allow to sit for about 3 minutes, then use a fork to stir; it will be thick and will likely look like it's not going to mix together but keep at it until smooth & creamy.
If your mixture doesn't melt down, microwave in 10 second increments at 50% power, stirring in between each increment until smooth.

To decorate:

Spoon 1 tablespoon of chocolate ganache on each cookie and top with rainbow chip sprinkles. Place in refrigerator for 30-60 minutes to help the ganache harden.
I recommend refrigerate the cookies as they get even better & fudgier when chilled! You can also keep them at room temperature for up to 2 days, if desired.

Last Step! Please leave a review and rating letting me know how you liked this recipe! This helps my small business thrive so I can continue providing free recipes and high-quality content for you.

Notes

Smaller cookies: For smaller cookies, use a 2-tablespoon scoop and bake for 8-10 minutes.
Cocoa Powder: I use and recommend Hershey's Special Dark Cocoa powder to give them a moist, rich flavor. You can substitute for regular unsweetened cocoa powder, just note that your cookies will have a puffier texture and won't have the iconic brownie taste.
Rainbow chip sprinkles: You can find rainbow chip sprinkles at Michaels, Amazon, or one of my favorite budget-hacks is to get a box of Pillsbury Funfetti brownie mix (at most grocery stores!) and use the packet inside. You can then just keep the brownie mix for another time.

Nutrition information is calculated using an ingredient database and should be considered an estimate

Nutrition

Comments

4.97 from 539 votes (344 ratings without comment)

Fudgy Cosmic Brownie Cookies