INGREDIENTS
1 cup
unsalted butter, room temperature, plus more for pans
2 1/2 cups
all-purpose flour (spooned and leveled, plus more for pans)
1/2 tsp
baking powder
1/2 tsp
baking soda
1 tsp
salt
1 tbsp
lemon zest
1 1/2 cups
sugar
2
large eggs plus 3 large egg yolks
1/4 cup
fresh lemon juice
1 cup
low-fat buttermilk
7 cups
confectioners' sugar
2
limes (juiced)
6 tbsp
lime zest
1 cup
butter (softened to room temperature)
8 tbsp
milk