Pound Cake

Recipe: 1 3/4 cups all purpose flour
2 teaspoons baking powder
1/8 teaspoon salt
1 cup (2 sticks) unsalted butter, room temperature
1 cup sugar 4 large eggs, room temperature
2 teaspoons pure vanilla extract (没这材料, 没放)
Zest of a lemon or orange (optional, 我也没放这个)
350 degree, bake for 50-60 minutes.