These cosmic brownies are a copycat of the Little Debbie’s version! They are fudgy, rich chocolate brownies, topped with chocolate ganache and rainbow candy coated chocolates.

Bite missing from cosmic brownies.

This homemade version of the Little Debbie brownies manage to make the classic treat even better! They have all of the chocolatey brownies goodness, but without the preservatives and artificial flavors. They are made with simple ingredients and no special equipment.

For more chocolate desserts, try Chocolate Mousse Cake, Chocolate Peanut Butter Cheesecake, and Moist Chocolate Cake.

Why This Homemade Cosmic Brownie Recipe Works

  • Better than Little Debbie cosmic brownies- This is a nostalgic treat, but the store-bought version can be disappointing to an adult. These are homemade brownies that bring the nostalgia and best traits, while being truly delicious!
  • Fudgy texture- The very important fudgy and chewy texture of these brownies is just right for matching cosmic brownies!
  • Simple ingredients- Simple ingredients of a homemade version make it much better. For example, this ganache is made with heavy cream and chocolate chips. It tastes much better than the shelf-stable preservative heavy version.
One cosmic brownie on its side.

Ingredient Notes for Homemade Cosmic Brownies

Here are some notes on the ingredients. For a full list of ingredients, check out the recipe card below.

  • Oil- Use canola oil or vegetable oil.
  • Unsalted Butter- Melt this before you need it so it can have time to cool.
  • Eggs- Take these out 2 hours before baking so it can get to room temperature.
  • Powdered sugar- For best results, be sure to sift this as clumps can cause gritty texture.
  • Unsweetened cocoa powder- I strongly recommend dutch process cocoa powder for a more rich chocolate flavor.
  • Chocolate chips- I used semi-sweet chocolate chips. I don’t recommend milk chocolate as the ganache will be a little bit too sweet.
  • Chocolate bar- I love the Lindt 78% bar, but any other chocolate bar can be substituted. Be aware that darker chocolate or lighter chocolate will adjust the flavor of the brownies some. Try to stick to semisweet chocolate.
  • Rainbow chips- I used these rainbow candy coated chocolate chips. If you have a similar rainbow candy you may substitute.

Ingredient Substitutions

  • Dairy free- You can use your favorite dairy free options for this recipe!
  • Gluten free- I haven’t tested this gluten free. Let me know if you do.

Step By Step Instructions – Chocolate Brownies

Here is how to make and bake the brownies for these cosmic brownies.

STEP 1: Prep. Preheat the oven to 350°F. Meanwhile, spray a 9X9 inch baking pan with baking spray. Line it with parchment paper along the bottom coming up 2 sides. Then, spray it again.

STEP 2: Dry ingredients. Sift the all purpose flour with the cocoa powder, cornstarch, and salt in a medium bowl. Set it aside. Now melt the chocolate bar in the microwave using 20 second intervals and stirring until it is melted fully.

STEP 3: Beat sugar and eggs. Use a mixer to beat the powdered sugar, granulated sugar, eggs, and egg yolks on high speed for 3 minutes. It should be pale and fluffy.

Wet ingredients in a bowl.
Brownie batter in a glass bowl.

STEP 4: Wet ingredients. Add the melted butter, oil, vanilla extract, and melted chocolate to the egg mixture. Mix them in on medium speed until combined. Then, add the dry ingredients and mix them in on low speed until just combined.

STEP 5: Pour batter. Take the bowl off the mixer and use a rubber spatula to scrape the sides and make sure the batter is fully mixed. Then, pour the brownie batter into the prepared pan.

Brownie batter in a pan.
Baked brownies on parchment paper.

STEP 6: Bake. Bake the brownies for 33-37 minutes. They are done when you insert a toothpick into the middle of the brownies and it comes out with moist crumbs.

Note that the brownies should be slightly underbaked as they will continue to bake as they cool.

STEP 7: Cool brownies. Let the brownies cool completely in the pan before removing them and decorating.

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Step By Step Instructions – Chocolate Ganache

Here is how to make the chocolate ganache for the cosmic brownies and decorate them.

STEP 1: Heat cream. Pour the chocolate chips into a heat-safe bowl. Add the heavy cream to a small saucepan and heat it on the stove on medium-low heat. Continue heating until it is steaming.

STEP 2: Melt ganache. Pour the hot cream over the chocolate chips and let them sit for 2 minutes. Then, use a rubber spatula to mix it until it is combined and smooth.

STEP 3: Decorate brownies. Pour the ganache over the brownies. Spread it over the edges gently using an offset spatula. Pour the rainbow candy coated chocolates on top. I recommend using 3/4 cup.

STEP 4: Set ganache. If serving immediately, place the brownies in the freezer for 10 minutes to set the ganache. If you are serving them later then set them in the fridge for at least 30 minutes. Then, cut them into bars and serve.

Expert Baking Tips

  • To make brownie recipes more fudgy you include more egg yolk and cornstarch.
  • The extra egg yolk adds more fats to the recipe which helps give that moist and soft texture compared to the tougher, more cakey texture from the gluten in the flour.
  • The cornstarch helps by breaking down the gluten strands from the flour as well leading to a more fudgy brownie.
  • When doing the toothpick test make sure that there is not wet batter. If there is you need to bake them for a few more minutes. There should be moist crumbs, but no batter.
Top view of brownies.

FAQ

Why did my brownies sink?

This means that the brownies were too under done. You will probably have extremely fudgy brownies. Bake the pan of brownies again for another 5-10 minutes to cook them more.

My brownies are very hard.

This means the brownies are over baked. Make sure when you bake these, the center is slightly under done. You should get moist brownie crumbs when testing with a toothpick.

Can I make this in an 8X8 pan?

Yes you can. It will just make thick brownies. They will require more bake time than a big pan due to being thicker.

Recipe Variations

  • Brownie bar shape- If you want to match the shape of Little Debbie’s cosmic brownies then you should cut them into longer skinner bars. Mine are only square from personal preference.
  • Rainbow sprinkles- If you do not have rainbow candy coated chocolates you can substitute rainbow sprinkles or mini M&M.

Special Tools

Three brownies on its side.

Storing and Freezing

Store these cosmic brownies in an airtight container like a cake carrier. Store in the fridge up to 5 days.

You can freeze the cosmic brownies in individual brownie slices. Place in an airtight container and freeze up to 30 days.

Stack of two cosmic brownies.

Other Brownie Recipes To Try

Try these brownie recipes too!

Make sure to leave a STAR REVIEW if you loved this recipe! Make sure to tag me on Instagram @stephaniesweettreats. To get more ideas follow me on Pinterest.

Bite missing from cosmic brownies.
5 from 2 reviews

Cosmic Brownies

These cosmic brownies are a copycat of the Little Debbie's version! They are fudgy, rich chocolate brownies, topped with chocolate ganache and rainbow candy coated chocolates.
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Ingredients
 
 

Chocolate Brownies

  • 1 1/2 cups White granulated sugar
  • 1/2 cup Powdered sugar
  • 3 Large eggs, room temperature
  • 1 Egg yolk, room temperature
  • 1/2 cup Unsalted butter, melted
  • 1/2 cup Oil, canola or vegetable
  • 1 tsp Pure vanilla extract
  • 3.5 oz Semi-sweet chocolate bar, melted. I used Lindt 78% chocolate
  • 1 cup All-purpose flour
  • 1 cup Unsweetened cocoa powder
  • 1 TBSP Cornstarch
  • 1 tsp Salt

Chocolate Ganache

Instructions
 

Chocolate Brownies

  • Preheat the oven to 350℉. Spray a 9X9 inch baking pan with baking nonstick spray. Line the bottoms and two of the sides of the pan with parchment paper. Spray again.
  • In a medium bowl, mix the flour, cocoa powder, cornstarch, and salt. Set aside. Melt the chocolate bar in the microwave for 20 second intervals until melted.
    3.5 oz Semi-sweet chocolate bar, 1 cup All-purpose flour, 1 cup Unsweetened cocoa powder, 1 TBSP Cornstarch, 1 tsp Salt
  • Using a mixer, beat the sugar, powdered sugar, eggs, and egg yolk on high speed for 3 minutes. It will become pale and fluffy.
    1 1/2 cups White granulated sugar, 1/2 cup Powdered sugar, 3 Large eggs, 1 Egg yolk
  • Add in the melted butter, oil, vanilla, and melted chocolate. Mix on medium until combined. Add in the dry ingredients and mix on low speed until just combined.
    1/2 cup Unsalted butter, 1/2 cup Oil, 1 tsp Pure vanilla extract
  • Take the bowl off the mixer and use a rubber spatula to scrape the sides and bottom of the bowl. Pour the brownie batter into the prepared pan.
  • Bake for 33-37 minutes. Bake until a toothpick inserted comes out with moist crumbs. You want to underbake these, so it finishes baking as it cools.
  • Cool completely in the pan before removing and decorating.

Chocolate Ganache

  • Pour the chocolate chips into a bowl. Add the heavy cream to a small saucepan. Heat on medium-low heat until hot and steaming.
    1 cup Semi-sweet chocolate chips, 1/2 cup Heavy cream
  • Pour hot cream over the chocolate chips and let it sit for 2 minutes. Use a rubber spatula to mix until combined and smooth.
  • Pour the ganache over the brownies. Use an offset spatula to gently spread to the edges. Pour the rainbow candy coated chocolates on top. I like a lot of them, so I used 3/4 cup.
    Rainbow candy coated chocolates
  • Place the brownies in the freezer for 10 minutes if serving immediately to set the ganache. If serving later, place the brownies in the fridge for at least 30 minutes before cutting into bars.

Notes

Flour- Make sure flour is spooned and leveled or use a kitchen scale. Compacted flour can dry out the brownies and cause them to be cakey.
High altitude baking- Add an extra 1 TBSP of flour.
Pull out dairy ingredients 2 hours before baking.
Calories: 322kcal, Carbohydrates: 38g, Protein: 3g, Fat: 21g, Saturated Fat: 9g, Polyunsaturated Fat: 3g, Monounsaturated Fat: 8g, Trans Fat: 0.3g, Cholesterol: 36mg, Sodium: 151mg, Potassium: 165mg, Fiber: 3g, Sugar: 23g, Vitamin A: 308IU, Vitamin C: 0.04mg, Calcium: 23mg, Iron: 2mg
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