For the Cake:
1 2/3 cups all-purpose flour 200g
1 cup granulated sugar 200g
1/4 tsp baking soda 1g, heaping
1 tsp baking powder 4g, heaping
3/4 cup unsalted butter 171g, room temperature
3 egg whites room temperature
1 tbsp vanilla extract 15mL
1/2 tsp salt 3g
1/2 cup sour cream 120mL, room temperature
1/2 cup whole milk 118mL, room temperature