Fresh-Squeezed Mimosa Cupcakes

Bahan-bahan (14 porsi)

• 1 and 3/4 cups (207g) cake flour (spooned & leveled)
• 1/2 teaspoon baking powder
• 1/4 teaspoon baking soda
• 1/4 teaspoon salt
• 1/2 cup (8 Tbsp; 113g) unsalted butter, softened to room temperature
• 1 cup (200g) granulated sugar
• 3 large egg whites
• 1 teaspoon pure vanilla extract
• 1 and 1/2 Tablespoons orange zest
• 1/3 cup (80g) full-fat sour cream*
• 2 Tablespoons (30ml) juice from a valencia orange*
• 1/2 cup (120ml) champagne (use your favorite)
• 3/4 cup (180ml) champagne (use your favorite)
• 1 cup (16 Tbsp; 226g) unsalted butter, softened to room temperature
• 4 cups (480g) confectioners’ sugar
• 1 teaspoon pure vanilla extract
• optional garnish: orange slices and gold sprinkles