Birthday cake brownies are fudgy chocolate brownies and confetti cookies layered together in this easy-to-make recipe for any occasion, not just birthdays!
These birthday cake brownies are half birthday cake cookies and half brownies, with lots of rainbow sprinkles in between.
They have a quick prep time, don't require a mixer, and are made with kitchen staples making these birthday brownies one of my favorite recipes ever.
Great for any occasion, not just birthdays, and one that everyone will love time and time again!
For more brownie recipes, try Cheesecake Marble Brownies, Salted Caramel Pretzel Brownies, Oreo Brookies, and Miso Brownies.
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why you'll love these birthday cake brownies
- Easy: These homemade brownies are made from scratch with no mixer, no long prep time, and simple pantry ingredients (similar to my Biscoff brownies!).
- Layered brownies: They have layers of chewy cookie dough, rich fudgy brownie batter, and tons of rainbow sprinkles!
- Brownie birthday cake: Not a fan of cake? I always make my cake batter macarons or these birthday cake brownies for the non-cake lover who still wants a fun celebratory dessert!
- Perfect for any occasion: I know they are technically birthday brownies, but it doesn't have to be a birthday in order to eat them! Cut them into mini bite-sized brownies and stash them in your freezer for your next chocolate craving.
ingredient notes
Rainbow sprinkles: I tested these birthday cake brownies with nonpareil sprinkles, but they tend to bleed and discolor the batter. I recommend using Rainbow Jimmy sprinkles instead!
Unsweetened cocoa powder: Dutch cocoa powder is best for a rich and fudgy brownie. I don't recommend substituting it!
Light brown sugar: Light or dark brown sugar can be used in this recipe.
Semi-sweet chocolate chips: You can substitute the semi-sweet chocolate with dark or bittersweet chocolate for a less-sweet brownie.
Full ingredient measurements and instructions can be found in the recipe card below!
recipe instructions
STEP ONE: In a large bowl, whisk together the light brown sugar, white sugar, vanilla extract, egg, and egg yolk until light and fluffy (image 1 below).
STEP TWO: Stream the melted butter into the eggs and sugar, whisking constantly until completely combined.
Then use a rubber spatula to fold in the all-purpose flour, salt, baking powder, and rainbow sprinkles until just combined (image 2 below).
STEP THREE: Pour all but about â…” cup of the batter into a lined square 8x8 baking pan and use an offset spatula to evenly fill the pan (image 3 above).
STEP FOUR: In another medium bowl, whisk together the egg and granulated sugar until light and fluffy.
Melt the butter and chocolate chips together and then stream them into the bowl while whisking constantly. Fold the all-purpose flour, cocoa powder, and salt into the batter with a rubber spatula until just combined (image 4 above).
STEP FIVE: Evenly spread the brownie batter on top of the cookie dough with an offset spatula (image 5 below).
STEP SIX: Use a spoon to dollop the rest of the cookie dough on top, then add a few extra rainbow sprinkles (image 6 above).
Bake the bars at 350 F/180 C for 26 minutes, or until a toothpick inserted into the center comes out with just the tip smeared in chocolate.
STEP SEVEN: Let the brownies cool completely on a wire cooling rack, then cut into 25 mini brownie bites or 9 regular-sized brownies (image 7 above).
expert brownie baking tips
- Use a kitchen scale: Baking with a scale is faster, easier, and overall much more accurate than cup measurements.
- Whisk the eggs and sugar: Whisking the eggs and sugar in both batters first will give you the coveted shiny crinkle tops!
- Don't overbake them: It's better to underbake brownies for the moist and gooey centers! The toothpick should have some smeared chocolate on it but not thick batter. If it's clean, they are overbaked.
- Cut after cooling: Wait to cut the brownies until after they are completely cool otherwise they will be too gooey and fall apart. I know it's hard to wait but it's so worth it!
recipe faqs
Store leftovers in an airtight container at room temperature for 2-3 days. You can also freeze them in an airtight container or freezer bag for up to 1 month!
Yes! You can double the recipe and bake it in a 9x13 dish, the baking time may need to be adjusted.
You could definitely substitute the rainbow jimmies for another kind of sprinkle, although I would keep in mind that some sprinkles like non-perils can bleed into the batter when mixing and discolor it.
I have not tested this recipe with gluten-free flour but would love to hear how it turns out!
I have not tested this recipe with other sprinkle variations. I don't recommend using nonpareils as they will bleed into the batter and discolor it!
more brownie recipes to try
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!
Recipe 📖
Birthday Cake Brownies
Equipment
Ingredients
For the Cookie Batter
- ½ cup unsalted butter melted
- ½ cup + 1 tbsp light brown sugar packed
- ¼ cup granulated sugar
- 1 large egg
- 1 large egg yolk
- 1 teaspoon vanilla extract
- 1 cup + 2 tbsp all-purpose flour
- ¼ teaspoon baking powder
- ½ teaspoon salt
- ¼ cup + 2 tbsp rainbow sprinkles
For the Brownie Batter
- 4 tablespoon unsalted butter melted
- â…“ cup semi-sweet chocolate chips
- ¼ cup + ⅛ cup granulated sugar
- 1 large egg
- 1 teaspoon vanilla extract
- ¼ cup all-purpose flour
- ¼ cup unsweetened dark cocoa powder
- ¼ teaspoon salt
Instructions
Making the Cookie Batter
- Preheat the oven to 350 F/180 C and line a square 8x8 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.½ cup + 1 tablespoon light brown sugar, ¼ cup granulated sugar, 1 large egg, 1 large egg yolk, 1 teaspoon vanilla extract
- Stream the melted butter into the bowl while whisking constantly until completely combined.½ cup unsalted butter
- Fold the flour, baking powder, salt, and rainbow sprinkles into the batter until just combined.1 cup + 2 tablespoon all-purpose flour, ¼ teaspoon baking powder, ½ teaspoon salt, ¼ cup + 2 tablespoon rainbow sprinkles
- Spread all but about â…” 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 tablespoon unsalted butter, â…“ cup semi-sweet chocolate chips
- In another medium bowl, whisk together the sugar, vanilla extract, and egg until fluffy, about 1 minute.¼ cup + ⅛ cup granulated sugar, 1 large egg, 1 teaspoon vanilla extract
- Stream the melted butter and chocolate into the bowl, whisking constantly until completely combined.
- Fold the flour, cocoa powder, and salt into the batter until just combined.¼ cup all-purpose flour, ¼ cup unsweetened dark cocoa powder, ¼ teaspoon 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 26 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!
Notes
- If you don't have a scale, use a spoon to fluff the flour first, then spoon it into your measuring cup.Â
recipe notes
- Use a kitchen scale: Baking with a scale is faster, easier, and overall much more accurate than cup measurements.
- Whisk the eggs and sugar: Whisking the eggs and sugar in both batters first will give you the coveted shiny crinkle tops!
- Don't overbake them: It's better to underbake brownies for the moist and gooey centers! The toothpick should have some smeared chocolate on it but not thick batter. If it's clean, they are overbaked.
- Cut after cooling: Wait to cut the brownies until after they are completely cool otherwise they will be too gooey and fall apart. I know it's hard to wait but it's so worth it!
The calorie information provided for the recipe is an estimate.
Leann says
Would it be ok to make the batter ahead and put it in the fridge overnight to bake in the morning?
Cambrea Gordon says
Hi Leann! I actually haven't tried this, but it should be okay. The tops may not be as shiny though, and they may require a longer bake time.
Sarah says
Are these supposed to cool in the pan? Or take out of the pan onto a wire rack to cool?
Cambrea Gordon says
Hi Sarah, let them cool in the pan on a wire rack- once cooled you can take them out of the pan.
Emilee Campbell says
Should the cookie batter be like normal cookie batter that will keep its shape? Or should it be a little runny? When I made it my cookie batter was on the runny side 🤔
Cambrea Gordon says
Hi Emilee! The cookie batter initially is thinner but firms up as it sits while you are assembling/making the brownie batter 🙂
Nicole says
If you are doubling then what size of pan do you use
Cambrea Gordon says
I would bake them in a 9x13 pan if doubling! 🙂
Emily says
These were delicious! Thank you so much for having the ingredient measurements embedded within the recipe. It made it so easy to follow without having to scroll back and forth!
Jill says
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
Cambrea Gordon says
This is such a kind review, thank you SO much Jill! I'm so thrilled you enjoyed them 🙂
Amy says
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 🙂
Daniel Robins says
How long do the brownies last roughly? Is it best to keep them in the fridge?
Cambrea Gordon says
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!
Daniel Robins says
Great, thank you!
Sarah says
These are absolutely delicious! They took a little longer to make with the two batters but it was worth it. My boys and their friends loved them.
Janice says
Can I use dark brown sugar?
Cambrea Gordon says
Definitely!