buttermilk cupcakes with swiss meringue frosting

Ingredients For buttermilk cupcakes with swiss meringue frosting

• 3 c

  cake flour
• 1- 1/2 c

  all-purpose flour
• 3/4 tsp

  baking soda
• 2-1/4 tsp

  baking powder
• 1-1/2 tsp

  sea salt
• 1 c

  unsalted butter, at room temperature
• 2 Tbsp

  unsalted butter, at room temperature
• 2-1/4 c

  sugar
• 5

  eggs, at room temperature
• 3

  egg yolks, at room temperature
• 2 c

  buttermilk, at room temperature
• 2 tsp

  vanilla
• FROSTING
• 5

  egg whites
• 1 c

  sugar
• 2 Tbsp

  sugar
• pinch salt
• 1 lb

  unsalted butter, at room temperature
• 1-1/2 tsp

  vanilla