Homemade Little Debbie Cosmic Brownies

Growing up, I loved Little Debbie Oatmeal Creme Pies and Cosmic Brownies so much.

Show me a box of either, and I could show you a pile of cellophane wrappers minutes later.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

Although it’s been years since I’ve had a storebought Cosmic Brownie, I had a craving for them and decided to try my hand at a homemade version.

This isn’t the first Little Debbie snack I’ve recreated. A few months ago I made Homemade Little Debbie Star Crunch and recently posted a collection of 25 Copycat Recipes. Apparently I like trying to re-invent the wheel.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

In terms of authenticity, I give them an 8 out of 10, with easy tweaks noted below to bring that score higher.

In terms of being a fabulous brownie overall, I give them a 10 out of 10. This brownie base is likely to become my new go-to. I loved everything about these brownies.

I created this brownie base by adapting my two favorite brownie bases, Fudgy Nutella Brownies and The Ultimate Fudgy Caramel Brownies. I’d like to make all 3 at once and do side-by-side comparisons, and I’ll get to that right after I budget in money for a new pants wardrobe.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

Both of my previous brownie bases use melted butter and a whisk, so they come together in minutes in own bowl, without needing a mixer. From there, I took my favorite things from each recipe – such as a 9×9 pan and using both brown and granulated sugars from Fudgy Nutella; and two eggs, cocoa powder, and espresso powder from The Ultimate.

The brownies are dark, dense, rich, the edges are just a bit chewy, with a moist and ultra-fudgy interior. There’s zero traces of cakiness and the fudge factor reigns supreme.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

I love the recipe and don’t want to change a thing but in order to make them more authentic, use natural unsweetened cocoa powder rather than Hershey’s Special Dark Cocoa Powder,  and increase the flour by about 1/4 cup. Cosmic Brownies aren’t as dark and are slightly more cakey, but I prefer darker and fudgier to lighter and cakier.

Baking them in a 9×9 pan was my preference, but if you want brownies closer to the real deal, use a 9×13 pan. I don’t like brownies that are on the thin side.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

The ganache layer is a bit thicker and when it comes to chocolate, thicker and more is better in my book, but use less if you wish.

I used more M&M minis than you’d find on Cosmic Brownies because skimpy isn’t an option. Note that when using M&Ms, they fade. The same thing happened when I made this Frozen Chocolate Pudding and Wafer Cake. The color starts leeching out as they sit on top of chocolate or post-refrigeration when coming back up to room temp. Not a huge deal, but something to mention.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

The benefit is that as they sit on the ganache, they soften a bit and become chewy rather than crunchy. The texture of chewy M&Ms is just fabulous and is like nothing I’ve ever had, which more than makes up for their slightly muted color.

As the ganache sets up, it remains soft and firms up just enough to not make a total mess when slicing the brownies. I hate it when the top layer of chocolate cracks, and this isn’t that kind of chocolate.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

Upon biting into a dense yet chewy brownie, soft ganache squishes and almost squirts between your teeth. And there’s chewy, ganache-softened M&M’s.

It’s the best texture party ever. Ever.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

I may be biased, but these are way better than Cosmic Brownies.

And quite possibly, they’re the best brownies I’ve ever had.

Homemade Little Debbie Cosmic Brownies - Recipe at averiecooks.com

Homemade Little Debbie Cosmic Brownies - If you've never had a Cosmic Brownie, change that asap! If you have, then you know how dangerously good it is to be able to make them at home!

Homemade Little Debbie Cosmic Brownies

I’ve always loved Little Debbie Cosmic Brownies and this homemade version is even better than the real thing. The brownies are dark, dense, and rich. The edges are just a bit chewy, with a moist and ultra-fudgy interior. There’s zero traces of cakiness and the fudge factor reigns supreme. They’re fast and easy to make, and come together in minutes in one bowl, without a mixer. The ganache is the perfect rich and luxurious compliment to the intensely chocolaty brownies. They’re quite possibly they’re the best brownies I’ve ever had.

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For the Brownies
3/4 cup unsalted butter (1 1/2 sticks), melted
2 large eggs
1 cup granulated sugar
2/3 cup light brown sugar, packed
2 tablespoons coffee or water (coffee leftover from the morning brew is fine)
2 teaspoons vanilla extract
3/4 cup unsweetened natural cocoa powder or dark cocoa powder (I used Hershey’s Special Dark)
1 teaspoon instant espresso granules (make sure it’s instant so it dissolves), optional but recommended
3/4 cup all-purpose flour

For the Ganache
1 1/2 cups semi-sweet chocolate chips
1/2 cup half-and-half or cream (I used half-and-half)
1 cup M&M minis (they’re sold in small tubes and I used 1 1/2 tubes; regular size M&Ms may be substituted)


  1. For the Brownies – Preaheat oven to 350F. Line a 9-by-9-inch baking pan with aluminum foil, spray with cooking spray; set aside.
  2. In a large, microwave safe bowl, melt the butter, about 90 seconds on high power.
  3. Add the eggs, sugars, coffee, vanilla, and whisk to combine.
  4. Add the cocoa powder, instant espresso, and whisk until incorporated, free from lumps, and smooth. It could take a few minutes if your cocoa powder is lumpy.
  5. Add the flour and stir until it’s just incorporated; don’t overmix.
  6. Turn batter out into prepared pan, smoothing the top lightly with a spatula. Bake for 25 to 29 minutes, or until top has just set, isn’t jiggly in the center, and a toothpick inserted in the center comes out clean or with a few fudgy moist crumbs, but no batter. I baked mine for 26 minutes. Allow brownies to cool completely in pan. While brownies cool, make the ganache.
  7. For the Ganache – Add chocolate chips to a medium, microwave-safe bowl and heat on high power for 1 minute to soften chips. They won’t be melted, this is okay. Don’t stir; set bowl aside.
  8. Heat cream in a glass measuring cup or microwave-safe bowl until it begins to bubble and show signs of just beginning to boiling, about 1 minute on high power.
  9. Pour cream over chocolate chips and let stand for 5 to 10 minutes.
  10. With a whisk, beat mixture until silky, smooth, and combined. If your mixture isn’t smoothing out, heat in 15-second bursts in the microwaves until it can be stirred smooth.
  11. Pour ganache over mostly cooled brownies (after about 30 minutes is fine; they don’t have to be completely cooled). Smooth ganache lightly with a spatula or offset knife.
  12. Evenly sprinkle with M&Ms. Cover pan with a sheet of foil to prevent fridge smells, and place pan in refrigerator until ganache sets up before slicing and serving, at least 2 hours. Do not slice into them until the ganache has set; feel free to make these in advance and store them in the fridge; they get better with time. Brownies will keep airtight for 1 week at room temperature, for 2 weeks in the refrigerator, and for up to 6 months in the freezer. I highly recommend storing them in the refrigerator because having a slight chill to brownies this rich and fudgy is almost imperative.

Recipe from Averie Cooks. All images and content are copyright protected. Please do not use my images without prior permission. If you want to republish this recipe, please re-write the recipe in your own words, or simply link back to this post for the recipe. Thank you.

Only Eats

Related Recipes:

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Fudgy Nutella Brownies with Cream Cheese Frosting

The Ultimate Fudgy Caramel Brownies

Chocolate Cake with Chocolate Ganache – The best, fastest, and easiest chocolate cake

Soft and Chewy Brownie Cookies

Frozen Chocolate Pudding and Wafer Cake (No-Bake, 3 ingredients)

Cosmic Brownie Fan? Other favorite storebought treats you grew up eating?

I know there will be some people who say they’ve never tried a real Cosmic Brownie. Well, now you can just make these instead.

Thanks for the entries in the Peanut Butter Comfort Cookbook and KitchenAid Hand Blender Giveaway and in the Favorite Mini & Petite Treats and Cookbook Giveaway

195 comments on “Homemade Little Debbie Cosmic Brownies”

  1. Super easy, and omg delish! Followed recipe to a T, wouldn’t change a thing. Thank you!

  2. Hi Averie! Simply delicious! It’s my first time to make some brownies. Used this base with oreos and mallows, next thing was they were asking for the recipe. Thank you so much! More power!

  3. These are definitely the fudgiest brownies I have ever eaten! So moist, thick and chewy, I’m taking them to 2 of my friends who love brownies – I know they will be a hit. Thanks again, Averie, your recipes never disappoint!

  4. Hey Averie, these truly look from the cosmos! Absolutely heavenly! One quick question, will the 25% fat cream work for the ganache? Or would it get too runny?

  5. I have made these TWICE this week, one for a birthday treat and one for a BBQ and they are so delicious; a hit with adults and little ones! This will be my go-to brownie recipe from now on! Next time,  I’m adding a peanut butter swirl to the ganache. Thanks for a fabulous recipe! 

  6. Wondering if this batter would work in an 8×8 inch pan or is that pushing it lol

  7. Made these brownies for the third time, and of course, they were the hit of the party! I was cooking for a crowd, so I followed the recipe and doubled the amounts. I baked them in a 9×13 pan, however I think next time I double the recipe I would bake them on a half sheet tray to make them thinner. Doubling the recipe in a 9×13 made for a super thick brownie (not the worst thing in the world!) I baked them for about 35-40 mins and they were beautiful and fudgy. The only change I made; I substituted nestle “bunch a crunch” candies for the m&ms. I would highly recommend this to others as they hold their shape and crunch for days and days, so the added texture is awesome! Just wanted to share for others who are thinking of doubling this scrumptious recipe! 

  8. Tried these for the first time today! I didn’t have any coffee or instant espresso, so I switched out the coffee for water and omitted the instant espresso; I think the flavor is nice and rich as is! I don’t really like frosting on most desserts, even as a kid I scraped the frosting off of the Little Debbie brownies, so I omitted the ganache and just put some fun sprinkles and they were still delicious! I’m excited to see how the flavor changes after being refrigerated overnight. Thanks for another great recipe!

  9. This recipe is perfect. I omitted the Espresso and used water, but it was still incredible!!! So rich and chocolatey. Also, I’ve seen a few people ask about using an 8×8. I made mine in an 8×8 and they took about 5-10 extra minutes in the oven and are a bit thicker, but very good. I haven’t had a little Debbie in years, but remember loving them as a kid and this homemade version tops those for sure. Thank you so much for this amazing recipe!

  10. I made the mistake of making these when I was on maternity leave – since I was home alone, I ate the whole pan in just a few sittings ? Now I’m making them to take to Thanksgiving. Move over pumpkin pie, the world’s best brownies are coming through! Thanks for the recipe!

  11. These are so so yummy!  Thanks for a great recipe!

  12. Another amazing recipe! These were so good and only got better with time in the fridge. I have struggled with brownie recipes before but these were perfect and I can’t wait to make them again!

    Rating: 5
  13. I totally remember having these as a kid but not very often. It’s been years since I had one. I’m going to have to give this recipe a try.

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