Vanilla Cupcake – 1 1/2 cups (182g) cake flour spooned and leveled – 1 cup (200g) granulated sugar – 2 tbsp dry milk powder*** – 1 tsp baking powder – 1/2 tsp baking soda – 1/4 tsp kosher salt – 6 tbsp unsalted butter, softened – 3 tbsp vegetable oil – 1/4 cup water, warm – 1/2 tsp vinegar – 1/2 cup (120g) sour cream, room temp – 2 large eggs + 1 egg yolk, room temp – 1 tbsp vanilla bean paste Vanilla Bean Buttercream – 1 cup (220g) unsalted butter, softened – 6 cups (660g) powdered sugar – 3–4 tbsp milk – 1/2 tbsp vanilla bean paste