• 1 cup (2 sticks) unsalted butter, room temperature
• 2/3 cup powdered sugar
• 2 1/4 cups all purpose flour
• 2 cups sugar
• 4 large eggs
• 7 tablespoons fresh lemon juice with pulp
• 1/4 cup finely grated lemon peel
• 1 teaspoon baking powder
• Additional powdered sugar
Preheat oven to 350°F. Using electric mixer, beat butter in large bowl until fluffy. Beat in 2/3 cup powdered sugar. Add 2 cups all purpose flour, 1 cup at a time, beating until moist clumps form. Using back of fork, press dough over bottom of nonstick 13x9x2-inch metal baking pan. Bake crust until light golden, about 20 minutes.
Meanwhile, beat 2 cups sugar and eggs in medium bowl until blended. Beat in fresh lemon juice with pulp, lemon peel, and baking powder, then remaining 1/4 cup all purpose flour for filling.
Pour lemon filling over hot crust. Bake until filling is set in center and begins to brown on top, about 20 minutes. Transfer pan to rack and cool completely. (Can be made 1 day ahead. Cover and refrigerate.)
Cut pastry into 24 bars. Transfer lemon bars to serving platter and dust with additional powdered sugar.