Rum Cake recipe slightly adapted from Gimme Some Oven 2  1/2 Cup cake flour 1 1/4 tsp. baking powder 1/4 tsp. baking soda 1 tsp. kosher salt 1 3/4 Cups sugar, divided (use 1/4Cup  for egg whites) 3 egg whites, room temp pinch of cream of tartar 6 egg yolks, room temp 10 Tbsp….