Birthday cake brownies combine fudgy chocolate brownies and confetti cookies in this easy-to-make recipe for any occasion, not just birthdays!
After working in many bakeries, I’ve realized not everyone wants a funfetti sprinkle cake for their birthday. That’s where the inspo for this recipe came in. Part birthday cake cookie, part brownie (stuffed with rainbow sprinkles, of course), these birthday cake brownies are the ultimate birthday dessert!
With no mixer required, they are super easy to make. This recipe is a great alternative to a birthday cake!
Table of Contents
Ingredient Notes and Substitutions
Rainbow sprinkles: Use rainbow jimmy sprinkles and avoid nonpareil sprinkles because they bleed into the batter. You can also change the color for Christmas, Independence Day, or Valentine’s Day!
Unsweetened cocoa powder: We use Dutch-processed cocoa powder for a rich chocolate flavor, like in my espresso brownies. Regular cocoa powder can be used as a substitute.
Light brown sugar: The molasses in the sugar helps keep the birthday cake brownies soft and chewy. You can use either light brown sugar or dark brown sugar.
Chocolate chips: Melted chocolate chips give them a super fudgy texture. For a less-sweet brownie, substitute the semi-sweet chocolate chips with dark chocolate chips or bittersweet chocolate chips.
Full ingredient measurements and instructions can be found in the recipe card below!
Recipe Instructions
Step 1: Whisk the wet ingredients. In a large bowl, whisk the light brown sugar, granulated sugar, vanilla extract, egg, and egg yolk until light and fluffy. (Image 1 below)
Step 2: Stream in the melted butter. Stream the melted butter into the bowl, whisking until combined. (Image 2 below)
Step 3: Fold in the dry ingredients. Fold in the all-purpose flour, salt, baking powder, and rainbow sprinkles until combined. (Image 3 below)
Step 4: Spread the cookie dough in the pan. Use an offset spatula to spread all but 2/3 cup of the batter into the prepared baking pan. Set the rest aside. (Image 4 above)
Step 5: Whisk the brownie batter ingredients. Whisk together the egg, sugar, and vanilla until fluffy. Then, stream in the melted chocolate. (Image 5 below)
Step 6: Fold in the dry ingredients. Fold in the all-purpose flour, cocoa powder, and salt until combined. (Image 6 below)
Step 7: Layer the brownie batter. Pour the brownie batter on top of the cookie layer and spread it evenly to the edges. (Image 7 above)
Step 8: Bake the birthday brownies. Use a spoon to dollop the reserved cookie dough on top, then cover it with extra rainbow sprinkles. Bake until a toothpick inserted comes out with the tip smeared in chocolate. Let the pan cool on a wire rack before slicing! (Image 8 above)
Pro Tips for Baking Brownies
Use a kitchen scale. Baking with a scale is my #1 baking tip! If you don’t have a scale, use a spoon to fluff the flour first, then spoon it into your measuring cup.
Use cold eggs: For those bakery-style shiny crinkle tops, use cold eggs and whisk them until light and fluffy.
Bake them in a metal pan. I highly recommend using a metal baking pan, not glass or ceramic, as they conduct heat differently and require a longer baking time.
Don’t overbake them! Underbaking brownies is important for achieving a moist, fudgy, and gooey texture. If you prefer a more set brownie, give it a few minutes longer in the oven!
Cut the brownies after cooling: It’s important to wait until they are completely cool before cutting them; otherwise, they will fall apart.
Use a sharp knife for clean cuts: For bakery-worthy slices, run a sharp knife under hot water and wipe it clean between cuts.
Storage, Freezing, and Doubling
Storage: Once completely cool, store birthday cake brownies in an airtight container at room temperature for 2-3 days.
Doubling the recipe: Click the 2x butter on the recipe card and bake them in a large 9×13 baking dish. I highly recommend using a metal baking pan, not glass or ceramic, as they conduct heat differently.
Freezing: Store the cut or uncut brownies in an airtight container or freezer bag for up to 1 month.
FAQs
Overbaking the brownies or incorrectly measuring the dry ingredients can produce a dense, dry, or cakey texture. Use a kitchen scale and underbake the brownies for the best results!
A trick I learned working in bakeries is to use a splash of clear vanilla extract or birthday cake extract in the batter. You can find both of these extracts in online baking stores like Olive Nation.
I don’t recommend making them ahead of time, as the texture of the bars is different.
Look for the edges of the brownies to start to crack. You can also stick a toothpick or skewer into the center; if it comes out covered in a few moist crumbs, it’s done baking!
More Fudgy Brownie Recipes
- Cheesecake marble brownies
- Salted caramel pretzel brownies
- Miso brownies
- Oreo brookies
- Biscoff brownies
If you tried this or any other recipe on my website, please let me know how it went in the comments below, I love hearing from you! Also, please leave a star rating while you’re there! You can also tag me on Instagram or Facebook so I can check it out!
Birthday Cake Brownies
Equipment
Ingredients
For the Cookie Batter
- 1/2 cup unsalted butter, melted
- 1/2 cup + 1 tablespoon light brown sugar, packed
- 1/4 cup granulated sugar
- 1 large egg
- 1 large egg yolk
- 1 teaspoon vanilla extract
- 1 cup + 2 tablespoons all-purpose flour, *See notes below for measuring*
- 1/4 cup + 2 tablespoons rainbow sprinkles
- 1/2 teaspoon fine sea salt
- 1/4 teaspoon baking powder
For the Brownie Batter
- 4 tablespoons unsalted butter, melted
- 1/3 cup semi-sweet chocolate chips
- 1/4 cup + 1/8 cup granulated sugar
- 1 large egg
- 1 teaspoon vanilla extract
- 1/4 cup all-purpose flour
- 1/4 cup unsweetened dark cocoa powder
- 1/4 teaspoon fine sea salt
Instructions
Making the Cookie Batter
- Preheat the oven to 350 F/180 C and line a square 8×8 baking pan with parchment to line all four sides.
- In a large bowl, whisk together the light brown sugar, granulated sugar, egg, egg yolk, and vanilla extract until fluffy, about 1 minute.1/2 cup + 1 tablespoon (126 g) light brown sugar, 1/4 cup (50 g) granulated sugar, 1 (55 g) large egg, 1 (17 g) large egg yolk, 1 teaspoon vanilla extract
- Stream the melted butter into the bowl while whisking constantly until completely combined.1/2 cup (113 g) unsalted butter
- Fold the flour, baking powder, salt, and rainbow sprinkles into the batter until just combined.1 cup + 2 tablespoons (142 g) all-purpose flour, 1/4 teaspoon baking powder, 1/2 teaspoon fine sea salt, 1/4 cup + 2 tablespoons (66 g) rainbow sprinkles
- Spread all but about 2/3 cup of the cookie batter evenly into the baking pan with an offset spatula.
Making the Brownie Batter
- Melt the butter and chocolate chips together until smooth.4 tablespoons (57 g) unsalted butter, 1/3 cup (75 g) semi-sweet chocolate chips
- In another medium bowl, whisk together the sugar, vanilla extract, and egg until fluffy, about 1 minute. Stream the melted butter and chocolate into the bowl, whisking constantly until completely combined.1/4 cup + 1/8 cup (83 g) granulated sugar, 1 (55 g) large egg, 1 teaspoon vanilla extract
- Fold the flour, cocoa powder, and salt into the batter until combined.1/4 cup (30 g) all-purpose flour, 1/4 cup (20 g) unsweetened dark cocoa powder, 1/4 teaspoon fine sea salt
- Pour the batter on top of the cookie batter in the pan and spread it evenly with an offset spatula. Use a spoon to dollop the rest of the cookie batter on top of the brownie layer, then sprinkle with more rainbow sprinkles.
- Bake the brownies for 25-30 minutes or until a toothpick inserted into the center comes out with just the tip smeared in chocolate. Let them cool completely on a wire rack before cutting, then enjoy!
Video
Notes
Tried this recipe?Leave a comment below & tag @cambreabakes on social!
If you are doubling then what size of pan do you use
I would bake them in a 9×13 pan if doubling! 🙂
I don’t often comment on baking blogs but wanted to make sure that everyone who reads this knows: these are absolutely delicious! Some of the best brownies I have ever made and received many complements. I have no doubt that this recipe should go viral, will definitely make again. I made a double batch in a glass pan and the baking time was about 30 minutes for those who are wondering
This is such a kind review, thank you SO much Jill! I’m so thrilled you enjoyed them 🙂
Made these for a friend’s birthday party. Everyone is asking for the recipe because they were such a hit!! Will be making this again for sure 🙂
How long do the brownies last roughly? Is it best to keep them in the fridge?
It’s best to store them at room temperature in an airtight container, ziplock bag, or wrapped tightly in their baking pan. They will last about 2-3 days!
Great, thank you!
Can I use dark brown sugar?
Definitely!