Brownie Birthday Cake Bars Recipe
Brownie Birthday Cake Bars- When brownie meets cake literally! These brownies are soft and fudgy topped with a thin chocolate frosting and sprinkles.
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I know cakey brownies aren't for everyone, but I also know there are people out there who absolutely LOVE them! And if you're one of those people, I made these Birthday Cake Brownie Bars just for you!
Imagine if a chocolate cake and a brownie had a baby. This would be it! These brownies have the rich chocolate flavor of a classic brownie but with a soft, tender, cake-like texture. It's almost like you're eating a slice of chocolate cake and a brownie at the same time!
And because we're making these into birthday cake brownies, we're topping them with a fluffy, lightly sweetened chocolate buttercream and colorful sprinkles. They're simple, delicious, and perfect for celebrating!
This small-batch recipe makes just 9 brownie bars, so you don't have to bake an entire birthday cake when you're craving something sweet.
Why You'll Love These Brownie Birthday Cake Bars:
- Soft and cakey texture: If you prefer cakey brownies over dense, fudgy ones, you're going to love these! They're soft, tender, and packed with chocolate flavor.
- Easy to make: You don't need any complicated techniques to make these homemade birthday brownies.
- Perfect small batch: This recipe makes 9 generous brownie bars in an 8×8-inch baking pan. It's perfect for small celebrations or when you don't need a whole cake.
- Chocolate buttercream frosting: The fluffy chocolate frosting adds just the right amount of sweetness without being overly rich.
- Great for any occasion: Despite the name, these birthday cake brownies aren't just for birthdays! They're perfect for potlucks, parties, gifting, or simply enjoying at home.
Brownie Birthday Cake Bars Ingredients and Substitutions
- Butter: Melted butter helps create a rich chocolate flavor and adds moisture to the brownies.
- Dark chocolate: I used dark chocolate for a deeper chocolate flavor. You can substitute semisweet chocolate if you prefer something a little sweeter.
- Granulated and brown sugar: Both sugars add sweetness to the brownies, while brown sugar also contributes moisture. Dark brown sugar or light brown sugar will both work great.
- Cocoa Powder: Dutch Cocoa Powder is more vibrant and stronger in flavor
- Oil: Using oil alongside butter helps keep the brownie bars soft and moist.
- Eggs: Eggs help bind everything together and contribute to the brownies' structure.
- Vanilla extract: A little vanilla enhances the chocolate flavor.
- Chocolate buttercream: A simple combination of butter, melted chocolate, vanilla, and powdered sugar creates a fluffy frosting.
- Sprinkles: Because what's a birthday cake without sprinkles? Use any colors you like to match the occasion!
How to Make Birthday Cake Brownie Bars
Preheat Oven to 325F.
Melt the butter in the microwave or in a small saucepan until completely melted and hot.
Chop the chocolate bar into small pieces and place them into a heatproof bowl. Pour the hot melted butter over the chocolate and let it sit briefly before stirring until smooth.
Set the chocolate mixture aside to cool slightly.
To the mixing bowl, combine the granulated sugar, brown sugar, oil, eggs, and vanilla extract. Mix until everything is well combined.
Add the dry ingredients to the chocolate mixture. Using a spatula, gently fold everything together until no dry streaks remain.
Line an 8×8-inch baking pan with parchment paper, leaving some overhang on the sides to make removing the brownies easier.
Pour the brownie batter into the prepared pan and spread it evenly.
Bake for approximately 20 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs and no wet batter.
Allow the brownies to cool completely in the pan before frosting.
In a large mixing bowl, beat the softened butter until creamy.
Add the cooled, melted chocolate and vanilla extract. Mix until everything is fully incorporated.
Gradually add the powdered sugar and continue beating until the buttercream becomes smooth, light, and fluffy.
Once the brownies have completely cooled, spread the chocolate buttercream evenly over the top using an offset spatula.
Finish with your favorite colorful sprinkles!
Slice into 9 squares, serve, and enjoy!
Tips and Tricks for the Best Cakey Brownies
Don't overmix the batter. Once you add the dry ingredients, gently fold until just combined. Overmixing can make your brownies tougher instead of soft and tender.
Avoid overbaking. Even though these are cakey brownies, you still want them to stay moist!
Use parchment paper. Leaving a little parchment hanging over the sides of your baking pan makes it much easier to lift the brownies out for slicing.
Let the melted chocolate cool before making the frosting. Hot chocolate can melt the softened butter and leave you with a runny buttercream.
How to Store Birthday Cake Brownie Bars
Room Temperature: Store the frosted brownies in an airtight container at cool room temperature for up to 2–3 days.
Refrigerator: For longer storage, refrigerate the brownies in an airtight container for up to 5 days. Let them sit at room temperature before serving so the brownies and frosting can soften.
Freezer: These birthday brownie bars freeze beautifully! Store them in an airtight, freezer-safe container for up to 1–2 months for the best quality.
If you're short on freezer space, refrigerate the frosted brownies until the buttercream firms up. Individually wrap each bar tightly in plastic wrap, then place them in a freezer-safe zip-top bag.
Whenever you're craving something sweet, simply thaw a brownie and enjoy!
Birthday Cake Brownie Bars FAQ
Can I use semisweet chocolate instead of dark chocolate?
Absolutely! I used dark chocolate for a deeper chocolate flavor, but semisweet chocolate works just as well. Just keep in mind that the brownies may taste slightly sweeter depending on the chocolate you use.
Do I have to make the chocolate buttercream frosting?
Nope! These cakey brownies are delicious on their own. If you're looking for a simple chocolate treat without the extra frosting, feel free to skip it.
But if you're making them for a birthday or special celebration, I highly recommend keeping the frosting and sprinkles!
Can I make these brownies ahead of time?
Yes! You can bake the brownies a day in advance and frost them once they've completely cooled. Store them in an airtight container until you're ready to serve.
More Brownie Recipes You'll Love
If you love these birthday cake brownie bars, make sure to check out a few of my other favorite brownie recipes!
- Copycat Cosmic Brownies – For those who love rich, chocolatey brownies with a nostalgic twist!
- Small Batch Chewy Fudgy Brownies – Perfect for anyone who prefers a rich, chewy, fudgy brownie instead of a cakey one!
Brownie Birthday Cake Bars Recipe
Ingredients
- ¾ cup All purpose flour
- ½ teaspoon Baking powder
- 2 Large eggs
- ¾ cup Granulated Sugar
- ¼ cup Dark Brown sugar
- ¼ cup oil neutral
- 1 teaspoon vanilla extract
- ⅔ cup dark chocolate chopped (chocolate of preference)
- 4 tablespoon Unsalted melted
- 3 tablespoon Dutch cocoa powder
Chocolate Frosting
- ⅓ cup semisweet chocolate
- 1 teaspoon vanilla extract
- 4 tablespoon butter softened
- ½ cup powdered sugar
- sprinkles
Instructions
Brownies
- Preheat your oven to 325°F. Line an 8×8-inch baking pan with parchment paper, leaving some overhang on the sides for easy removal.
- Melt the butter in the microwave or a small saucepan until hot. Place the chopped chocolate in a large heatproof mixing bowl and pour the hot melted butter over it. Let it sit for 1–2 minutes, then stir until the chocolate is completely melted and smooth. Allow the mixture to cool slightly.
- Once the chocolate mixture has cooled slightly, add the granulated sugar, brown sugar, oil, eggs, and vanilla extract. Whisk until everything is fully incorporated and smooth.
- Add the dry ingredients directly to the chocolate mixture. Using a spatula, gently fold until no dry streaks remain. Be careful not to overmix.
- Bake the brownies. Pour the brownie batter into the prepared baking pan and spread it evenly. Bake at 325°F for approximately 20 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
- Cool completely. Remove the brownies from the oven and allow them to cool completely before adding the chocolate buttercream.
Chocolate Buttercream Frosting
- In a large mixing bowl, beat the softened butter until smooth and creamy.
- Add the melted chocolate and vanilla extract. Beat until fully incorporated.
- Gradually add the powdered sugar and continue beating until the buttercream becomes light, smooth, and fluffy.
Assemble the Brownie Bars
- Once the brownies have completely cooled, spread the chocolate buttercream evenly over the top using an offset spatula.
- Top with colorful sprinkles or your favorite decorations.
- Lift the brownies out of the pan using the parchment paper. Slice into 9 equal squares and enjoy!
Nutrition
Recently in my kitchen Recipes:
Should I use salted or unsalted butter
Hey Amy! Sorry this is one of the very first recipes I published on my blog. It's in the works of a makeover. But either is fine. The recipe doesn't call for salt but salt would do great in this recipe!
I love cakey brownies! does this use dutch or natural cocoa powder? can we add a little salt? dark brown or light brown sugar?
How long to let them cool before adding frosting?!
Hey Sarah,
You'll have to wait for them to fully cool down before you can frost so the frosting doesn't melt. It might be 30 to 40 minutes before you can. You can also place in the fridge or freezer to make it cooler faster too.