Best Lemon Bars

INGREDIENTS

1/2 cup

unsalted butter

1/2 cup

all-purpose flour

1/2

cup whole wheat pastry flour (or additional all-purpose flour)

1/4

cup powdered sugar, plus additional for serving

1/4 tsp

plus 1/8 teaspoon kosher salt, divided

1 cup

granulated sugar

2 tsp

lemon zest (about three-quarters of 1 large lemon)

large eggs, at room temperature

1/4 cup

freshly squeezed lemon juice (from about 1 large lemon)

1/2 tsp

baking powder