These Birthday Cake Brownies are an easy, yet delicious dessert to celebrate any occasion. A layer of funfetti cookies topped with fudgy brownies and mixed with sprinkles and mini chocolate chips bakes into a delicious surprise of flavors and textures.

Birthday cake brownies topped with sprinkles and cut into squares.

A good, fudgy chocolate brownie with a rich chocolate flavor (like one bowl brownies) is a staple for any baker. Layer it with funfetti batter and you have a delicious combination of flavors.

No need to wait to celebrate a birthday with these birthday cake brownies. They are perfect for celebrating any day and this easy recipe uses staple baking ingredients.

About This Recipe

TEXTURE: Soft and chewy with a light crunch of sprinkles and mini chocolate chips and finished with a crinkly brownie top.
FLAVOR: Combination of rich, fudgy chocolate with sweet sugar cookie dough.
EASE: Simple and fun!
TIME: Done in under 1 hour.
HIGHLIGHT: The perfect brownie birthday cake that celebrates any occasion!

Before You Begin

Take out the following baking equipment:

8x8-inch square Baking Pan
Parchment paper
Whisk
Small bowl
Medium bowl
Medium microwave-safe bowl
Large bowl
Rubber spatula

Read the recipe from start to finish.

Ingredient Notes

Semi-sweet chocolate bar adds a rich flavor to brownies. It’s the preferred choice for its higher quality and better results compared to chocolate chips.
A bit of cornstarch produces thicker brownies and improves the shiny crust.
Adding an egg yolk to the cookie batter produces a light and chewy texture. Because of the extra fat, it also enriches the flavor of the cookie layer.

How to Make This Recipe (step-by-step)

Whisk together the cookie batter dry ingredients and set aside. In a separate bowl, whisk together the sugar, egg, egg yolk and vanilla until the mixture becomes light and creamy. Add the melted butter and combine.
Add the dry ingredients and sprinkles to the butter mixture and mix just until combined.

Mixing bowl with wet ingredients for cookie dough. — Sugar, egg, yolk, vanilla and butter combined.

Mixing bowl with funfetti cookie dough. — Sugar, egg, yolk, vanilla and butter combined.

For the brownie batter, melt the chocolate and butter together until completely smooth.
Whisk the sugar and egg together constantly for 2-3 minutes until pale in color.

Note: Whisking the eggs and sugar together until thickened and a pale yellow color is referred to as the “ribbon stage”. The mixture will fall from the whisk like ribbons. This technique creates taller and creamier brownies with a shiny crust.

Add the melted chocolate to the sugar and egg and combine.
Gently fold in the dry ingredients along with the mini chocolate chips

Mixing bowl with whisked eggs and sugar for brownie batter. — Sugar and egg at ribbon stage.

Mixing bowl with brownie wet ingredients. — Sugar and egg at ribbon stage.

Scoop the cookie batter into a parchment-lined 8x8-inch square pan, leaving spaces between each scoop.
Add the brownie batter to the pan to fill the gaps and spread it into an even layer. Sprinkle with the sprinkles and mini chocolate chips.

Baking pan with scoops of cookie dough. — Scooped cookie dough.

Baking pan with birthday cake brownie batter. — Scooped cookie dough.

Bake in a preheated 350°F/177°C oven for 25 to 28 minutes.

Substitutions and Variations

For an even fudgier brownie, substitute brown sugar for the granulated sugar in the brownie batter.
Dutch-process cocoa powder can be substituted for unsweetened (also known as natural) cocoa powder. This will result in darker brownies with an even more intense chocolate flavor.
Add a layer of crushed Oreos between the cookie and brownie layers for a fun surprise.

How to Store

Keep these funfetti brownies stored in an airtight container for up to 3 days at room temperature or refrigerated for up to 1 week.

Baking Success Tips and Takeaways

Use a kitchen scale to measure your ingredients for consistent results. Using cup measurements can cause variations in ingredients, and too much flour will result in a more cakey brownie and less fudgy brownie.
Rainbow sprinkles (or any color sprinkles) work best in these birthday brownies. Non-perils can bleed into the batter.
Allow the brownies to cool completely before slicing. The chocolate and butter need to solidify before slicing.
To double these birthday cake brownies, bake in a 9x13-inch rectangular baking pan. You will have to increase the time slightly to account for the extra batter.

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Please leave a starred rating and comment below if you make these Birthday Cake Brownies. I love reading your feedback! And if you'd like to make this recipe later, don't forget to pin it on Pinterest! Happy Baking!