Go Back
birthday cake for one

Birthday Cake for One

Print Recipe
Easy, one bowl birthday cake for one's birthday. If they are so inclined to share, it should only be with 2 others, max.
Course Dessert


  • mixer for batter



  • 1 stick unsalted butter 113g
  • 1/2 teaspoon fine sea salt
  • 2 teaspoons imitation vanilla or pure vanilla extract or a combination
  • 1 1/2 cups organic powdered sugar 200g
  • 1-2 tablespoons buttermilk milk, heavy cream, or sour cream


  • 1/4 cup unsalted butter 55g
  • 1 1/2 tablespoons coconut oil *see notes below for substitutions
  • 1/2 cup granulated sugar 100g
  • 1/4 teaspoon baking soda
  • 1/2 teaspoon baking powder
  • 2 teaspoons imitation vanilla
  • 1/4 teaspoon fine sea salt
  • 2 large egg whites
  • 1 cup cake flour 130g
  • 1/2 cup buttermilk 120g
  • 3 tablespoons sprinkles
  • 3 tablespoons mini chocolate chips


  • Make the buttercream: in a small bowl, use a hand mixer to beat the butter with the salt and vanilla until light and fluffy, at least 3 minutes. Add the powdered sugar and beat to combine. Add 1 TB of the milk and if it doesn’t smooth out, add another TB. Set the buttercream in an airtight container until cake is ready to be assembled.
  • Preheat oven to 325 and butter and flour an 8×8″ square pan.
  • In a bowl, beat the butter, oil, salt and vanilla with the sugar until very light and fluffy, 3-5 minutes.
  • Add the egg whites one by one, allowing the first to fully incorporate before the second. Beat until very fluffy.
  • Add the cake flour, baking soda and powder and buttermilk all at once and beat to combine.
  • Fold in the sprinkles and chocolate chips, if using.
  • Pour into cake pan and bake for 30-35 minutes, until a cake tester comes out clean from the center.
  • When the cake is completely cool, use a ring to punch out four circles (this is easier to do if the cake has been frozen for a bit). You now have four tiny cake layers. Level them with a cake leveler or knife so they are the same height.
  • Stack the cake layers with buttercream. Between each layer you’ll want 1-2 tablespoons buttercream. Frost the sides.


If you don't have or don't want to use coconut oil and don't mind a yellowish tint to the cake, skip the coconut oil and use full eggs (including the yolks) for this recipe.