INGREDIENTS
FOR THE CAKE/CUPCAKES 1 3/4 cup (245 g) basic gum-free gluten free flour (162 g superfine white rice flour + 54 g potato starch + 29 g tapioca starch/flour)
1/4 tsp
xanthan gum
2 tbsp
cornstarch (can’t have cornstarch? try arrowroot and let us know how it goes!)
1 tsp
baking powder
1/2 tsp
baking soda
1/2 tsp
kosher salt
1 cup
granulated sugar
1
egg (60 g, out of shell), separated + 1 egg white, at room temperature
8 tbsp
unsalted butter, at room temperature
2/3 cup
sparkling wine (can substitute ginger ale for an alcohol-free version)
FOR CHAMPAGNE FROSTING 1 1/2 cups (300 g) granulated sugar
1/2 tsp
cream of tartar
1/4 cup
sparkling wine (can substitute ginger ale for an alcohol-free version)
5
egg whites (150 g total)
24 tbsp
unsalted butter, cubed and kept cool (but not cold)
1/8 tsp
kosher salt