Birthday Cake Brownie Recipe That’s a Party in a Pan

Step outside of the box with this crowd-pleasing birthday cake brownie recipe.

Updated January 9, 2024
Brownie Birthday Cake Combination

In the 90s, cookie cakes reigned supreme, and in the 2000s ice cream cakes were all the rage. But what your childhood birthday parties were missing out on was brownie cake deliciousness. Break free from tradition and send your tastebuds soaring with our homemade birthday cake brownie recipe.  

Crowd-Pleasing Birthday Cake Brownie Recipe 

Keep your loved ones on their toes this year with an unexpected brownie cake that's sure to delight everyone's sweet tooth. This recipe makes about 24 servings. You can store these sweets for up to three days at room temperature or four to five days in the refrigerator. 


  • 2 cups white sugar
  • ¼ cup cocoa powder
  • 1 cup salted butter
  • 4 eggs
  • 2½ teaspoons vanilla extract
  • 1½ cups all-purpose flour
  • ½ to 1 cup of cake mix batter with sprinkles 


  1. Preheat the oven to 350°F
  2. In a large bowl, mix the sugar and cocoa powder. Set aside. 
  3. Place a double boiler on the stovetop over high heat. Add the butter and heat until melted. 
  4. Remove the butter and allow it a few minutes to cool.
  5. Once the butter's no longer piping hot, stir it into the sugar and cocoa powder mixture. 
  6. In a separate bowl, crack all four eggs and whisk together. 
  7. Slowly add eggs to the sugar and cocoa mixture, stirring as you pour.
  8. Add the vanilla extract to the mixture. 
  9. Using a stand or handheld mixer, beat until combined.
  10. Add flour and stir until well mixed.
  11. In another mixing bowl, prepare the sprinkle cake mix as instructed on the box. Set aside. 
  12. Grease a 9x13 cake pan or 10x15 bar pan.
  13. Pour the brownie batter into the cake pan first.
  14. Then, put dollops of the cake mix across the top of the brownie layer. 
  15. Use a knife to swirl the cake batter into the brownie mix. 
  16. Bake the brownie and cake batter mixture in the cake pan for 35-40 minutes or the bar pan for 30-35 minutes. Keep an eye on the brownies as your baking time may differ depending on your oven. 
  17. When the brownie cake is done and cuts clean, let it cool before slicing, frosting, and decorating. 
Quick Tip

This recipe also makes for a delicious cake base. Instead of cutting brownie slices, frost over the entire brownie cake and stack your favorite cake layers on top.  What's more fun than surprising your guests with a 2-in-1 dessert?

Related: 21 Alternatives for Birthday Cake That Are Still Sweet 

Accommodate Everyone's Tastes With Different Frosting Options

Frosting and candles can sell any kind of dessert as one perfect for a birthday party. Make all of your relatives happy by offering multiple frosting options to accommodate everyone's tastes.

Personalize Your Cake Bars With These Mix-in Ideas

If you don't want to cover up your beautiful concoction with a layer of frosting, you might want to consider throwing something else delicious into the batter. Stir in ½ cup of any of these dessert bar toppings if you want to take your birthday brownies to the next level.

  • Chopped peanuts
  • Chopped pecans
  • Chopped walnuts
  • Mini M&Ms
  • Chocolate chips
  • White chocolate chips
  • Crushed pretzels 
  • Crushed Andes mints
  • Crushed peppermints
  • Crushed Oreos
  • Mini Reese's Peanut Butter Cups
  • Crushed chocolate chip cookies

The Only Surprise Your Birthday Party Will Ever Need 

Birthday parties are all about having fun. Why not extend that energy into the kitchen and whip up this perfect birthday cake alternative? With bits of brownie and cake in every bite, this birthday dessert is sure to be a smashing success. 

Birthday Cake Brownie Recipe That’s a Party in a Pan