INGREDIENTS
1
and 3/4 cups (200g) cake flour
1/2 tsp
baking powder
1/4 tsp
baking soda
1/4 tsp
salt
1/2 cup
unsalted butter, softened to room temperature
1 cup
granulated sugar
3
large egg whites
1 tsp
vanilla extract
1
and 1/2 Tablespoons orange zest
1/3 cup
full-fat sour cream1
2 tbsp
juice from a Sunkist Valencia orange2
1/2 cup
champagne (use your favorite)
3/4 cup
champagne (use your favorite)
1 cup
unsalted butter, softened to room temperature
4 cups
confectioners' sugar
1 tsp
pure vanilla extract
optional garnish: orange slices and gold sprinkles (I used these sprinkles!)