These Rainbow Chip Brownies are homemade buttermilk brownies at their best. Made from scratch and topped with colorful candy sprinkles, these brownies look like Little Debbie’s Cosmic Brownies but taste worlds better!
There’s no such thing as too many brownies. From decadent Oreo Brownies to Chocolate Chip Zucchini Brownies–I’ve never met a brownie I didn’t like.
Why this Recipe is Best
Know what makes me extra happy? A hot cup of coffee and one of these Rainbow Chip Brownies.
- A childhood classic!
- Inspired by Cosmic Brownies from Little Debbie.
- Based on my favorite Buttermilk Brownie recipe.
- Rich homemade chocolate frosting.
- Sprinkled with Rainbow Chips!
No offense to Debbie and her baking skills but the packaged brownies I used to get in my lunch box just don’t hold a candle to these homemade brownies with rainbow chips.
I also have a homemade oatmeal cream pie recipe if you’re looking more more copycat recipes for nostalgic treats.
Ingredient Notes
Rainbow chips are not just any sprinkles. They’re little pieces of chocolate in a hard candy coating! I love them on brownies and they’re AWESOME mixed into frosting or cake batter too.
Buttermilk is the secret to amazingly moist brownies. It’s used in both the brownie batter and the frosting so the rainbow chip brownies stay soft and moist, even a few days after baking! Use our easy buttermilk substitute for a quick fix.
Dark chocolate cocoa powder tastes best in these brownies. Use a high quality brand like Rodelle or Ghirardelli if you can. Trust me–it makes a difference.
Easy Instructions
PRO TIP: Don’t have buttermilk? Make my easy buttermilk substitute with just milk and lemon juice (or white vinegar)!
Prepare the brownie batter:
Bring butter, cocoa powder and vegetable oil to a boil, then add it to a mixing bowl with eggs, buttermilk, sugar and vanilla. Gently stir in the dry ingredients to form a batter.
Bake:
Pour the batter into a parchment lined baking dish. Bake for 20 minutes and let the brownies cool.
Frost:
Combine all the frosting ingredients, except for the powdered sugar, in a sauce pan. Bring to a boil over medium heat whisking constantly. Pour the butter mixture into a bowl with the powdered sugar. Beat until the frosting is smooth and combined.
Spread the frosting over cooled brownies. Finally, sprinkle rainbow chips on top! w
Tips and Tricks
- Chill the brownies before cutting. These taste extra delicious served cold straight out of the fridge!
- Bake in a 13 x 9 baking dish. You’ll have plenty of thick, moist brownies to go around.
- How to store brownies: Stored in the fridge, rainbow chip brownies stay good for about 1 week. For longer storage, you can freeze them.
Recipe FAQs
You can find rainbow chips in the baking aisle at your grocery store. They’re usually near the chocolate chips. Or buy them online!
It’s up to you. To freeze frosting brownies, place a piece of wax paper over the frosting first. This prevents the frosting from becoming runny and goopy as it thaws.
A plastic knife works best for cutting brownies evenly without tearing or sticking. Make sure to wipe the knife clean after every cut for smooth, even edges.
Also: Do not skip the chilling! If you don’t chill these rainbow chip brownies, they’ll fall apart and get gooey when you try to cut them.
More Brownie Recipes
- Fudgy Zucchini Brownies: no one will know that you snuck in some veggies, these are still so decadent and sweet!
- Buckeye Brownies: fudgy brownies topped with a peanut butter filling. All covered in a rich, chocolate ganache!
- Chocolate Mint Brownies: sweet and minty, the perfect after dinner dessert!
More Easy Dessert Recipes
- Buttermilk Sheet Cake
- Blueberry Pie
- Rainbow Buttercream Board
- Cherry Cobbler
- Peanut Butter Cups
- Funfetti Dip
Rainbow Chip Brownies
Ingredients
For the Brownies:
- ½ cup unsalted butter
- ¼ cup dark chocolate unsweetened cocoa powder
- ½ cup vegetable oil
- 2 cups granulated sugar
- 2 large eggs
- ¼ cup buttermilk
- ½ teaspoon vanilla extract
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- ½ teaspoon kosher salt
- 1 cup semi-sweet chocolate morsels
For the Frosting:
- ½ cup unsalted butter
- ½ cup buttermilk
- ¼ cup dark chocolate unsweetened cocoa powder
- 4 cups powdered sugar
- 1 cup rainbow chips
Instructions
- Preheat oven to 400F. Line a 13×9-inch baking dish with parchment paper. Set aside.
- For the brownies, in a small saucepan over medium high heat, combine butter, cocoa powder and oil. Bring to a boil and remove from heat.
- In a large mixing bowl, combine granulated sugar, eggs, buttermilk and vanilla. Slowly whisk in the butter mixture. Add in flour, baking soda, and salt. Stir just until combined. Fold in chocolate chips.
- Pour into prepared baking dish and bake for 20 minutes. Remove from oven and cool.
- While cooling, prepare the frosting. Combine butter, buttermilk and cocoa powder in a small saucepan. Whisk over medium heat until mixture begins to boil. Remove from heat.
- In a mixing bowl, combine powdered sugar with butter mixture. Beat for several minutes until smooth. Pour over brownies. Sprinkle immediately with rainbow chips!
- Refrigerate for about 2 hours, until set. Cut and enjoy. I store these in the refrigerator for best results!
WHere do you buy rainbow chips?
I can usually find them in the baking aisle with the sprinkles!
My pet unicorn wants me to tell you she approves. 🙂
Haha, yes!
Ooo Buttermilk brownies! Never made them with buttermilk, but they look so delish. And I am SOOOOO jealous your weather has changed, still 85-90F here in So Cal… still hating turning the oven on!!
OMG OMG OMG OMG!!!! These look – UGH! I want. And then all the other recipes – SOOOO GOOOOD!!
haha, these are pretty fantastic 🙂
I’m not happy about the sudden cold snap, either, and I’m not even in Chicago. I used to go there all the time. I love the pizza! Miss it lots and lots.
These brownies are so happy. They might drive the chill away!
These are so fun and colorful! That gooey frosting looks divine!
I think that’s just human nature right? When we are hot we complain…when we are cold we complain…why can’t it just be 72 degrees all the time?? 🙂 At least we have rainbow chip brownies to make ourselves feel better 🙂
These are so happy-making! I have not ever seen Rainbow Chips; good golly, all I’ve been missing. Oh good, I just noticed Lauren above hasn’t seen them either. Thanks for the delish reicpe, weather update and the happy post.
I have never seen rainbow chips before! Just in time for my kids’ birthday cakes! And of course these amazing brownies!
Thanks for the brownie linky love 🙂 And yes Chicago weather is like that, it goes from hot to cold, overnight. None of those nice ‘fall’ days. It’ll be snowing next week. lol
I have never made brownies with buttermilk! I’ve tried a gazillion brownie recipes, but never with buttermilk. Now I think I have to!
So fun! Seeing a plate of these would definitely put a smile on my face 🙂
These brownies are just making me smile right now. Adorable.
Your weather situation in Chicago sounds a lot like Buffalo. This year, we went fro high 80’s to what feels like frigid weather. No sun. Rain. Can’t even mow the lawn. Hope our neighbors aren’t mad! Oh well, I’ll just make these brownies instead. Would you consider liking the bowl a workout? No. How about whipping around that spatula?
Oh I won’t complain to those of you in Buffalo!! You get serious amounts of snow there 🙂