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+ servings
Fudgy brownies on parchment paper, one has a bite taken out of it

Birthday Cake Brownies

Extra fudgy brownies stuffed with oreos and with a funfetti cake layer
Course Dessert
Cuisine American
Prep Time 25 minutes
Cook Time 50 minutes
Total Time 1 hour 15 minutes
Servings 16 bars
Calories 386kcal
Author Ella


  • 8x8 pan



  • 2 eggs room temperature
  • 1 egg yolk room temperature
  • ¾ teaspoon vanilla extract
  • ounces unsalted butter
  • ¼ cup cocoa powder dutch process
  • ½ cup all purpose flour
  • 4 ounces dark chocolate chopped
  • 1 teaspoon kosher salt
  • ½ cup light brown sugar
  • ½ cup granulated sugar
  • ¼ cup vegetable oil

Funfetti Layer

  • 9 oreos
  • 1 egg room temperature
  • ½ tablespoon vanilla extract
  • ½ cup light brown sugar
  • ¼ cup granulated sugar
  • 1 ⅛ cup all purpose flour
  • 6 tablespoon unsalted butter
  • ¼ teaspoon baking powder
  • ½ cup sprinkles


Make Funfetti Layer

  • Preheat oven to 350°F/175°C. Line an 8x8 pan with foil and set aside.
  • In a small saucepan melt your butter.
  • In a large jug, whisk together the sugars, vanilla, and salt. Add the egg and whisk until smooth.
  • Pour the butter into the jug and whisk.
  • Pour in the flour and baking powder, whisk until there are no more pockets of flour but don't overmix.
  • Fold in your sprinkles.
  • Pour the batter into the bottom of your pan. Place your oreos on top.


  • In a small bowl, whisk together the flour and salt.
  • In a large bowl, place your eggs, egg yolks, sugar, oil and vanilla extract. Mix together using a hand held mixer for about 6-8 minutes until well mixed. This is what will give you a thin crust on top!
  • Place a small saucepan with about an inch of water over medium/low heat until it begins to simmer. Place a heat proof bowl over it and melt your butter and chocolate together until smooth. Take off the heat.
  • Add in your cocoa powder to the butter and whisk until smooth.
  • Pour this chocolate mixture into your sugar mixture and whisk until smooth.
  • Fold in your flour mixture and mix until there are no more flour pockets.
  • Pour the brownie batter on top of the funfetti oreo layer. Bake for 45-50 minutes. The top should have crackled and a toothpick inserted will come out with a few crumbs. While still warm, you can sprinkles over extra sprinkles on top!
  • Let cool for several hours until you slice it into bars.


Butter: I use European style butter, like Kerry Gold, in my recipes. This will make your finished bake much creamier and richer.
Salt: If you don't have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt.
Cocoa Powder: I am using dutch process cocoa powder for this. If you live in Europe, this is just regular cocoa powder. 
Sprinkles: I don't recommend using nonpareils (the little circular balls) as they'll bleed quite a lot. 
Vegetable Oil: Use a neutral oil like canola oil, vegetable oil, or rapeseed oil 
Storage: Keep them in an airtight container, if you keep them at room temperature they’ll last about 3 days but in the fridge they’ll last about 5 days. 
Slicing: The brownies will continue baking when you remove them from the oven, so let them cool completely before you slice them. 


Calories: 386kcal | Carbohydrates: 46g | Protein: 4g | Fat: 22g | Saturated Fat: 13g | Trans Fat: 1g | Cholesterol: 75mg | Sodium: 203mg | Potassium: 134mg | Fiber: 2g | Sugar: 32g | Vitamin A: 438IU | Calcium: 35mg | Iron: 2mg