Tessa's Recipe Rundown
Taste: These homemade Cosmic Brownies have a much better chocolate flavor than the store-bought ones! No weird artificial flavors here.
Texture: Ultra-rich, fudgy, and chewy. So good.
Ease: Very easy!! Enjoy a batch of these in just over an hour.
Why You’ll Love This Recipe: An easy DIY version of your favorite nostalgic childhood treat.
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These Homemade Cosmic Brownies will evoke all those childhood memories of snacking on those little plastic-wrapped store-bought brownies – but these babies are SO much better!
Real, decadent, and satisfying chocolate, without all the crazy artificial ingredients.
When I was a kid in elementary school, I’d ALWAYS request a Little Debbie brownie as my special treat in my lunch box.
Before Cosmic Brownies, there were only the Little Debbie brownies with the nuts. I would always pick off all the nuts.
I knew I had to make my own version from scratch.
These little brownies are ultra-rich and fudgy, almost like candy. I got as close to the texture of the store-bought kind as I possibly could. I hope you love them as much as I do!
Sprinkle of Science
What are Cosmic Brownies?
Cosmic Brownies, created by snack company Little Debbie, basically summarize a childhood in the 1990s in each bite. They are chewy with a rich, fudgy frosting that’s dotted with rainbow crunch sprinkles. They come individually wrapped and are super sweet and quite artificial tasting.
In creating my copycat version, I opted for a fudgy chocolate ganache topping that delivers a much better burst of chocolate flavor.
Check out the side-by-side below – my homemade version is on the left and the store-bought is on the right:
Ingredient Notes for Success
Butter vs. Oil in Brownies: Which is Better?
Brownies made with butter are fudgier and softer than oil brownies. You’ll find these Cosmic Brownies call for all butter to provide the best flavor and melt-in-your-mouth texture.
Check out my Butter vs. Oil in Baking article for a full breakdown on each of these fats and how they affect tenderness, flavor, and texture in baked goods (and not just brownies).
Cornstarch + Corn Syrup = Secret Ingredients
There is a small amount of both cornstarch and corn syrup in this recipe to help make the brownies super chewy and fudgy.
Feel free to omit the corn syrup or use golden syrup if you prefer, but note that your brownies just won’t quite have that same Cosmic texture. Don’t skip the cornstarch – learn why cornstarch is important in brownie recipes here.
Extra Egg Yolk = Fudgy & Chewy!
You’ll notice in most of my brownie recipes I add an extra egg yolk. This adds fat and protein which translates to rich, fudgy, and chewy brownies.
How to Avoid Dry, Crumbly Cosmic Brownies
The key is to measure your dry ingredients properly. It’s super easy to accidentally add too much flour and cocoa powder – unless you use a digital kitchen scale to ensure 100% accuracy.
If you don’t have a scale, use the spoon and level method for both the flour and cocoa powder to ensure accuracy, and avoid dry, hard, cakey, or crumbly brownies. You can learn more about how to measure ingredients properly here.
The Best Brownie Baking Pan
- I highly recommend using a light-colored metal baking pan. This is my favorite baking pan for brownies, blondies, cheesecake bars, cookie bars, and more.
- Avoid using dark-colored metal pans; the darker the color, the more likely you are to burn the edges or have dry edges.
- Glass or ceramic baking pans will take LONGER to bake these brownies, and the texture may become dense and gummy. Learn more in my Glass vs. Metal Baking Pans article.
How to Cut Brownies Perfectly
Use a large sharp knife and run it under hot water, wiping it off completely between slices.
How to Store
Frosted, sliced brownies can be stored in an airtight container for 3 days at room temperature or for 1 week in the fridge. They are best served chilled, for maximum fudginess.
FAQs
I used to use Wilton Rainbow Crunch for topping Cosmic Brownies (as seen in the pictures here), but those are increasingly difficult to find. This Baker’s Choice version is available on Amazon, but feel free to use rainbow sprinkles, mini M&Ms, or whatever you like to top these brownies.
Yes, just not your brownies may not be as chewy. You can use golden syrup or invert syrup, instead.
Yes, simply double all ingredients and bake in a 9×13-inch metal baking pan, adding 2-3 minutes extra baking time.
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Ingredients
For the brownies:
- 10 tablespoons (142 grams) unsalted butter
- 1 cup (200 grams) granulated sugar
- 1/3 cup (67 grams) packed light brown sugar
- 3/4 cup plus 2 tablespoons (88 grams) unsweetened cocoa powder, sifted
- 1/2 teaspoon vanilla extract
- 2 large eggs plus 1 egg yolk
- 1 tablespoon corn syrup
- 2/3 cup (85 grams) all-purpose flour
- 1 tablespoon cornstarch
- 1/4 teaspoon fine sea salt
For the frosting:
- 1/2 cup heavy cream
- 1 1/2 cups (255 grams) semisweet chocolate chips
Rainbow Candy-Coated Chocolate Chips , or mini M&M’s, sprinkles, or other candy, for topping
Instructions
Make the brownies:
- Preheat the oven to 350°F. Line an 8-by-8-inch metal baking pan with parchment or foil and spray with cooking spray.
- In a large microwave-safe bowl, melt the butter for about 90 seconds on high power. Stir in the granulated sugar, brown sugar, and cocoa powder. If still very hot, let cool slightly before adding in the vanilla, eggs, egg yolk, and corn syrup. Stir until very well combined. Add in the flour, cornstarch, and salt and stir until just combined. Batter will be thick. Pour into the prepared pan and bake for 25 minutes. Let cool completely in the pan.
Make the frosting:
- Place the cream in a small microwave-safe bowl and microwave on high for 1 minute. Add in the chocolate chips. Let stand for 3 minutes before stirring until smooth. Pour over the cooled brownies and smooth evenly. Sprinkle with the Rainbow Candy-Coated Chocolate Chips. Refrigerate for 1 to 2 hours, or until the frosting is set, before cutting.
- Brownies can be stored in an airtight container for 3 days at room temperature and for 1 week in the fridge. Brownies are best served chilled.
Notes
Where to Find Rainbow Candy-Coated Chocolate Chips?
I used to use Wilton Rainbow Crunch for topping Cosmic Brownies, but those are increasingly difficult to find. This Baker’s Choice version is available on Amazon, but feel free to use rainbow sprinkles, mini M&Ms, or whatever you like to top these brownies.More Brownie Recipes:
- Best Chewy Brownies – my most popular recipe!
- Nutella Brownies
- Raspberry Brownie Recipe
- Toffee Brownies
- Malted Brownies
This recipe was originally published in 2014 and has been updated with recipe improvements and new photos. Photos by Ashley McLaughlin.
The most rich and delicious brownies you can find! And they are also perfect for back-to-school treats for lunch boxes. These brownies will more than satisfy any chocolate lover. Delish!
So glad you enjoyed this recipe, Jolyn! Thanks for the comment 🙂
These were delicious brownies, but tasted nothing like Cosmic Brownies. They had a gooey, rich texture and taste that was great but I could definitely see where I’d make these again for more of an adult dinner party than to replicate a favorite kids item.
This is one of my favourite brownie recipes. I decided to try a “healthier” version by using coconut cream instead of heavy cream. It turned out great!
This looks like a delicious recipe! But I was wondering do I need to use corn syrup? And if I don’t need to do I need to change any other measurements?
Please check out the pink tip box above the recipe, I talk about that 🙂
So I just poured the icing onto my brownies and just realized i forgot the vanilla will this mess up the whole taste of my brownies ?
I’m sure you’ve tried your brownies by now, what did you think? It’s a small amount of vanilla, so they’ll still taste chocolaty and delicious, but vanilla is a not only a great flavor addition but a great enhancer of other flavors as well. I’m sure next time you won’t forget 🙂
Dear Tessa,
I found this recipe thanks to google, because I had some left-over ganache from a bigger project, that I didn’t want to waste.
Wow. These are probably the fudgiest fuss-free brownies I’ve ever baked. No melting chocolate, no mixer necessary, plain and simple baking with amazing results! This may very well become my go-to recipe when I need my chocolate fix. Can’t wait to find out, what other delights I find on your blog!
Thank you and lots of love from Germany,
Jazz
I’m so happy to hear that, Jazz, you just made my day! These are a fave for sure! 🙂
Will dark corn syrup work with this recipe? Or is light corn syrup the only way to go ?
Free free to omit the corn syrup or use golden syrup if you prefer 🙂 I haven’t tried dark corn syrup, so I can’t say for sure but I would imagine the taste would be different due to the addition of molasses in dark corn syrup.
As a lifelong Little Debbie fan, I can honestly say these are 100x better! Perfectly fudgy and so easy to make!
Woohoo! So awesome to hear this 🙂
Hello, so excited to try this cosmic brownie recipe. My question is. Can this recipe be doubled for a 13×9 baking pan. It is glass. Which is better in your opinion. Glass or metal? I only have 1, 8 inch square pan. I will need to invest in more smaller pans. I love baking big. That way I can share with family and friends. Thanks for posting this recipe. My grandson has a sweet tooth like me
Hi LuAnn, yes, doubling this recipe would be perfect for a 9×13 pan. I think I responded to you earlier, but your comment was connected to someone else’s review so you must not have seen my response 🙂 I always recommend using a light-colored metal pan, like this one. Glass and ceramic pans take longer to bake and your brownies may not set properly in the center before the edges become overcooked and dry. Let me know how your brownies turn out — this would be a super fun recipe to make with your grandson! Good luck!
Do you also double the baking time if using a 9X13 pan?
Nope! Depending on the pan you use, you may have to add a few extra minutes to the original baking time, but otherwise, the timing stays the same 🙂
Hi there Tessa. I hope you had a wonderful Christmas and New Year. It’s been a while since I asked my question about the size of a baking pan and got your response. I ended up making these brownies with my grandson. He absolutely loves them. He just turned 9 in October. So I’m slowly introducing him to cooking and baking as I had done with my son( his daddy) and my daughter when they reached the age of 10. His mom doesn’t really cook. Mostly because she was never taught at home. In my opinion. Kids need to be taught the basics in life. Such as cooking, baking, sewing, chores. As well as general studies in school. Life skills. I’m ole school and try to pass on everything I learned when I was young. That I learned from my mom and grandma. Today’s kids are just plain self entitled lazy. No one wants to work. But yet they all want a paycheck/ money. Thanks again for sharing this recipe. I read a comment where a lady said the frosting was to sweet and was only going to use half of it the next time she made these brownies. I plan on doing the same. Both the brownies and frosting are amazingly delicious. I’m a Baker by trade. My specialty is Cheesecakes.
So glad you and your grandson had fun making these together! Thanks for the comment 🙂
Hello. You know the ole saying. Better late than never lol. I Finally got around to making these amazing brownies with my grandson today. They are super delicious and I made sure to share with my son, daughter and granddaughter. Unanimous vote Yes. But I will tell you. I used Hershey’s cocoa recipe to make the frosting. I cut back on the sugar here and there. They really are amazing. Thank you so much for sharing this recipe with everyone. I too follow your recipes and everyone of them is better than the last. Thanks again.
Can you freeze these brownies?
Absolutely! I’d cut them up ahead of time and make sure they’re in a sealed container!
is it still good without the m&m’s?
Absolutely!
I can’t wait to try your recipe. They look amazing. I spent some time reading the comments. Can this recipe be doubled for a 13x 9 pan? I did see where someone asked about using a glass pan and adding 15 minutes to the cooking time. Would it be better to use an aluminum foil pan from the grocery store. Over Using a glass pan. Thanks
Yes, this recipe could be doubled for a 9×13 pan 🙂 I always recommend using a light-colored metal pan, like this one. Glass and ceramic pans take longer to bake and your brownies may not set properly in the center before the edges become overcooked and dry. Let me know how your brownies turn out! Good luck!
I made these recently, on my daughter’s request, they did NOT disappoint! The recipe was easy to follow and did not have any issues. I think I had to bake an extra 5 minutes but other than that, everything else worked out perfectly. Thank you for all the recipes you share. My family has very much enjoyed them all! Keep up the the good work.