The Best Homemade Cosmic Brownies: Fudgy, Thick & TikTok Famous Little Debbie Copycat Recipe

Prepare for an extraordinary treat! These homemade cosmic brownies are unbelievably thick, decadently fudgy, and packed with rich chocolate flavor. This recipe isn’t just good; it’s 10 times better than any store-bought version and even went viral on TikTok, captivating over 13 million viewers! Each square is crowned with a silky, creamy chocolate ganache – a brilliant version made without heavy cream – and adorned with iconic rainbow chip sprinkles, making every bite truly out-of-this-world delicious.

Before you dive into baking, be sure to read through this entire post for essential tips, helpful step-by-step photos, a special discount code for those vibrant rainbow sprinkles, and answers to all your frequently asked questions!

Why Our Homemade Cosmic Brownies Outshine Store-Bought Versions

While the nostalgic charm of Little Debbie Cosmic Brownies holds a special place in our hearts, this homemade recipe takes everything you love about them and elevates it to an entirely new level. Here’s what makes our version truly superior:

1. Super Thick & Satisfying: Unlike the often thin and somewhat unsatisfying store-bought Little Debbie brownies, this recipe is specifically designed to deliver a wonderfully thick, substantial brownie experience. Baked in a 9×13 pan, these brownies boast a generous height, ensuring every bite is rich and satisfying – no paper-thin treats here!
2. Unmatched Fudginess: The secret to their incredible texture lies in a carefully crafted combination of ingredients. Melted butter, vegetable oil, a touch of cornstarch, an extra egg yolk, and high-quality Hershey’s cocoa powder work together to create that iconic, melt-in-your-mouth fudgy Cosmic Brownie texture that you’ll crave.
3. Effortless Ganache (No Heavy Cream Needed!): One of the biggest challenges with traditional ganache recipes is the need for heavy cream, an ingredient many of us don’t keep on hand. We’ve simplified this step by developing a luscious milk and butter ganache. This clever substitution means you can skip that extra trip to the store, saving you time and effort. While slightly softer than a cream-based ganache, it delivers an equally (if not more!) delicious and smooth chocolate topping. If you prefer a different frosting, we also have a rich brownie frosting recipe.
4. Authentic, Rich Chocolate Flavor: Let’s be honest, the cosmic brownies we adored as kids often don’t taste quite the same anymore – sometimes leaning towards an artificial, plastic-like flavor rather than true chocolate. This homemade rendition ensures a deep, rich, and genuinely chocolatey flavor that will remind you of the best childhood treats, but with an elevated, grown-up twist.

Watch my viral TikTok video below and see these amazing brownies come to life!

@designeatrepeat

Cosmic brownies…but 10x better 🌈💪 Tap green button on video for recipe! recipes baking littledebbie treatyourself cosmicbrownie

♬ Love You So – The King Khan & BBQ Show

Homemade Cosmic Brownie Ingredient Overview: Your Pantry Essentials

This section provides a detailed overview of the ingredients you’ll need and their roles. For precise measurements and condensed instructions, click here to jump directly to the full recipe card.

• Unsalted Butter: You’ll be melting this, so there’s no need to soften it to room temperature beforehand. Melted butter contributes significantly to the rich, fudgy texture of the brownies.
• Granulated Sugar & Brown Sugar: The combination of both sugars ensures a perfectly sweet brownie with a chewy depth. Granulated sugar provides crispness, while brown sugar adds moisture and a subtle caramel note.
• Eggs: You’ll need three large eggs, plus an extra egg yolk. The whole eggs provide structure and richness, while that additional egg yolk is a secret ingredient for an even chewier and fudgier brownie texture.
• Vanilla Extract: A crucial flavor enhancer, vanilla extract beautifully complements and deepens the chocolate flavor in the brownies.
• Vegetable Oil: This ingredient is key for keeping the brownies incredibly moist and fudgy. Omitting the oil would result in a drier, more cake-like brownie texture.
• Cornstarch: Another secret weapon for ultra-moist and fudgy brownies! Cornstarch helps tenderize the crumb and prevents the brownies from becoming dry. If you have a corn allergy, you can omit it, but expect a slight difference in texture.
• Salt: Essential for balancing the sweetness of the sugars and enhancing the overall chocolate flavor. Don’t skip it!
• Baking Soda: While only a small amount, baking soda provides a slight lift, contributing to the perfect brownie density without making them cakey.
• Hershey’s Cocoa Powder: As mentioned, I specifically tested and highly recommend Hershey’s 100% Cacao Natural Unsweetened for its superior flavor. Using generic or lower-quality cocoa can drastically diminish the taste, resulting in a less authentic chocolate experience. Consider this your friendly warning!
• All-Purpose Flour: Provides the necessary structure for the brownies, holding all that fudgy goodness together.
• Rainbow Chip Sprinkles: These are the iconic topping that gives cosmic brownies their signature look! You can find these vibrant sprinkles on Amazon, and sometimes at craft or grocery stores.
• For the Easy Chocolate Ganache: You’ll need semi-sweet chocolate chips (check the next section for notes on specific brands that perform best!), unsalted butter, and milk (whole milk or 2% is ideal for the best texture, but see the recipe card’s “notes” section for more details on milk choices).

Are you loving this copycat recipe for Cosmic Brownies and craving more nostalgic treats? I’m constantly working on new Little Debbie-inspired recipes. In the meantime, be sure to check out my incredible Homemade Oatmeal Creme Pies and the super quick Homemade Star Crunch recipe that you can whip up in the microwave!

Crafting the Easy Chocolate Ganache (Without Heavy Cream!)

This section contains crucial notes and clever tricks for achieving the perfect ganache. Please read carefully!

Heavy Cream vs. Milk: The Smart Swap for Convenience: The decision to use milk instead of heavy cream for this ganache was all about making this recipe as accessible as possible. Most home bakers, myself included, don’t regularly have heavy cream stocked in the fridge. By substituting with milk and butter, we achieve a wonderfully smooth, creamy, and utterly delicious frosting. The butter cleverly replaces the fat content typically found in heavy cream, resulting in a luscious topping that’s incredibly satisfying and soft.

Chill to Firm the Ganache for Perfect Slices: Because this is not a traditional heavy cream-based ganache, it won’t fully harden at room temperature. For beautifully set frosting and clean, crisp edges when slicing, chilling the finished brownies is a vital step. After spreading the ganache, refrigerate the brownies for 1-2 hours. This allows the frosting to firm up sufficiently. This chilling step is especially important if you aim for those picture-perfect, neat cuts. If left at room temperature, the ganache will naturally soften, so we highly recommend storing your frosted brownies in the refrigerator to maintain their firm texture and fresh appearance.

How Chocolate Chip Brands Affect Ganache Firmness: During our testing, we discovered that the brand of semi-sweet chocolate chips you choose can significantly influence how firm your ganache sets in the refrigerator. We rigorously tested this ganache recipe with four popular semi-sweet chocolate chip brands. Our findings showed that Nestle Toll House produced the firmest ganache, followed by Ghirardelli at a close second, Hershey’s in third, and Costco brand in fourth. While all brands delivered comparable taste (personally, I find Ghirardelli’s flavor to be excellent!), their setting properties did vary. Keep this in mind when selecting your chocolate chips!

For a Firmer Ganache That Hardens at Room Temperature: If your primary goal is a frosting that completely hardens and remains firm even at room temperature (ideal for stacking or transporting), you will need to use heavy cream. To prepare a traditional firm ganache, follow the instructions in the recipe card below, but substitute ½ cup of heavy cream for the milk and omit the butter. Use 1.5 cups of chocolate chips as specified.

How To Make Homemade Cosmic Brownies: A Visual Guide (Step-by-Step Photos!)

TThis section walks you through the process with helpful step-by-step photos. For the complete list of exact recipe amounts and detailed instructions, click here to jump down to the full recipe card.

Step 1: Melt Butter & Sugars, Then Mix the Brownie Batter

Begin by preheating your oven to 350°F (175°C). In a large microwave-safe bowl, combine your unsalted butter, granulated sugar, and light brown sugar. Microwave this mixture according to the recipe card’s instructions, stirring until smooth and glossy. Allow it to cool for a few minutes. Then, carefully stir in the eggs, extra egg yolk, vanilla extract, salt, baking soda, and cornstarch until just combined. Finally, fold in the cocoa powder and all-purpose flour by hand – remember, mixing by hand is key to avoiding over-aeration and ensuring a dense, fudgy brownie. Finish by mixing in the vegetable oil.

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Step 2: Prepare Your Pan and Spread the Batter

To ensure easy removal and clean cuts, lightly spray a light-colored metal 9×13 inch baking pan with nonstick cooking spray. Then, press a piece of parchment paper into the pan, covering the bottom and extending up the long sides to create a “parchment sling.” This sling will be your best friend when it’s time to lift the cooled brownies out. Evenly spread the thick brownie batter into the prepared pan, using an offset spatula or the back of a spoon to smooth the top.

Important Note on Pans: As discussed in our tips section, baking these brownies in glass or dark metal pans can lead to uneven baking, potentially causing the edges to overbake and become dry or bitter. If you only have a glass or dark metal pan, it’s even more crucial to line it thoroughly with parchment paper on all sides. You may also need to slightly reduce the baking time to prevent overbaking.

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Step 3: Bake to Perfection and Cool Completely

Place your prepared pan in the preheated oven and bake for 24-26 minutes. It’s crucial not to overbake these fudgy brownies! To check for doneness, insert a toothpick into the center – it should come out with moist crumbs attached, but not wet batter. Alternatively, gently shake the pan; the center should be set and not jiggly. Overbaking will compromise that irresistible fudgy texture you’re aiming for, resulting in drier brownies. Once baked, remove the brownies from the oven and let them cool completely in the pan on a wire rack. To speed up the cooling process once the pan is no longer hot to the touch, you can transfer it to the refrigerator. While the brownies cool, proceed to Step 4 to prepare your delicious chocolate ganache!

Step 4: Whip Up the Easy Milk & Butter Ganache

While your brownies are cooling, it’s time to prepare the simple yet decadent chocolate ganache. In a medium-sized bowl, combine your semi-sweet chocolate chips and chopped unsalted butter. In a separate, microwave-safe liquid measuring cup (ensure it’s at least three times taller than your milk line to prevent overflow during heating!), heat the milk for 1.5 to 2 minutes, or until it’s steaming and just begins to bubble. You can also heat the milk on the stovetop until it steams. Carefully pour the hot milk over the chocolate chips and butter – resist the urge to stir immediately! Let the mixture sit undisturbed for about 3 minutes. This allows the residual heat from the milk to melt the chocolate and butter. After 3 minutes, begin to stir with a whisk. It might look separated at first, but continue stirring gently until it transforms into a smooth, glossy, and creamy ganache. Allow the ganache to cool for approximately 30 minutes before spreading it over the completely cooled brownies.

Step 6: Cut & Savor Your Homemade Cosmic Brownies!

For the neatest, most professional-looking slices and clean edges, it is imperative to refrigerate your frosted brownies for at least 2 hours, or freeze them for about an hour, to ensure the frosting is completely set. Cutting them directly from the fridge or freezer is the secret to achieving those crisp, sharp cuts. After the brownies have been out at room temperature for a while, the frosting will naturally begin to soften. Therefore, for optimal presentation and texture, we recommend storing any remaining brownies in the refrigerator to keep them looking and tasting their best.

Pro Tip for Clean Cuts: To mimic the pristine edges of real Little Debbie cosmic brownies, use a large, sharp chef’s knife. Cut straight down in one decisive motion, avoiding any back-and-forth “sawing” motions. After each cut, wipe your knife clean with a damp cloth or paper towel. This technique prevents smudging and ensures each slice is perfectly crisp and beautiful!

Storage & Freezing: Keeping Your Cosmic Brownies Fresh

How Long Do These Fudgy Brownies Stay Fresh?

To ensure your homemade cosmic brownies retain their incredible taste and texture for as long as possible, it’s best to store them in an airtight container. When stored this way, they will remain delicious for 3-4 days at room temperature. However, if you want the ganache frosting to maintain its firm, set texture, storing them in the refrigerator is highly recommended. Properly stored in the fridge, these brownies will stay good for 4-5 days, possibly even longer, without losing their fudgy appeal.

Can Homemade Cosmic Brownies Be Frozen?

Absolutely! These fudgy brownies freeze exceptionally well, and surprisingly, their soft ganache actually makes them quite enjoyable straight out of the freezer – they won’t be rock hard! To preserve the frosting’s pristine appearance during freezing, here’s a helpful trick: First, place the brownies (unwrapped and uncovered) on a baking sheet and freeze them for 1-2 hours until the frosting is completely solid. Once firm, you can then transfer them to an airtight freezer-safe container or wrap them individually in plastic wrap and then foil. This prevents the frosting from smudging or sticking. These delightful fudgy brownies will keep beautifully in the freezer for 1-2 months. Beyond that timeframe, while still safe to eat, they may start to lose some of their moisture and become a bit drier.

Frequently Asked Questions About Homemade Cosmic Brownies: