Go Back
–+ servings

Birthday Sheet Cake

When it comes to birthday celebrations, nothing quite beats a homemade cake that's both simple and delicious. This Easy Birthday Sheet Cake with Vanilla Buttercream Frosting is the perfect choice for your next celebration or upcoming birthday parties. It’s a light and fluffy vanilla cake topped with creamy, smooth buttercream frosting—ideal for anyone craving a sweet treat without all the fuss.

Would you like to save this?

We'll email this post to you, so you can come back to it later!

Prep Time 10 minutes
Cook Time 35 minutes
Cooling Time 2 hours
Total Time 2 hours 45 minutes
Serving Size 24

Ingredients

  • 2¾ cups all purpose flour
  • 1 tsp baking powder
  • ½ tsp baking soda
  • ½ tsp salt
  • 1½ cup sugar
  • ½ cup butter (1 stick)
  • 4 eggs room temperature
  • ½ cup melted coconut oil or vegetable oil
  • ⅓ cup full-fat sour cream or plain yogurt, room temperature
  • 1½ tbsp pure vanilla extract
  • 1 cup whole milk room temperature

Vanilla Buttercream Icing

  • 1 cup unsalted butter (2 sticks), room temperature
  • 2½ cup confectioners' sugar
  • pinch of salt
  • 2 tsp pure vanilla extract
  • 1-2 tbsp heavy whipping cream or milk

Instructions

  • Preheat the oven to 350°F. Grease a 9x13-inch baking pan or line it with parchment paper and set aside.
  • In a medium bowl, whisk together the cake flour, baking powder, baking soda, and salt. Set aside.
  • In the bowl of a stand mixer, cream together the butter and sugar until light and fluffy, about 5 minutes
  • Add the eggs one at a time, beating well after each addition. Then, mix in the vanilla extract, sour cream, and coconut oil. Don't worry if the batter looks a bit curdled at this stage—it's totally fine. 
  • Scrape down the bottom and sides of the bowl as needed.
  • Gradually add the flour mixture in three parts, alternating with milk (start with flour, then milk, then flour, milk, and finish with flour). Mix until the batter is smooth and well-combined.
  • Transfer the batter to the prepared pan and spread it out evenly. Bake for 30 to 35 minutes at 350°F, or until a toothpick inserted into the center comes out clean with little to no crumbs
  • Allow the cake to cool completely on a wire rack (about 2 hours) before frosting.

Frosting

  • For the frosting, beat the butter on medium speed until light and fluffy, about 2 minutes. Add the confectioners’ sugar and salt, then mix on medium speed until fully combined.
  • Stir in the vanilla and 1 tablespoon of heavy whipping cream, mixing until incorporated. Scrape down the sides and bottom of the bowl as needed. If you prefer a thinner frosting, add an extra tablespoon of whipping cream.
  • Spread the frosting evenly over the cooled cake. Top with sprinkles, add birthday candles, and celebrate!