Directions
Preheat oven to 350 degrees. Butter an 8-inch square baking pan. In a medium bowl, whisk together 1 cup flour, 1/4 cup powdered sugar, grated lemon peel and salt. Cut in butter with a pastry blender until mixture resembles coarse crumbs. Knead dough in the bowl until it sticks together. Transfer dough to baking pan and press it evenly onto the bottom. Bake on a rack in the center of the oven for 25 minutes or until light golden brown. Let crust cool on a rack while you make the filling.
Whisk together remaining 1 1/2 cups powdered sugar, remaining 2 tbsp. flour and baking powder in a small bowl. Beat eggs with an electric mixer on high speed for about 2 minutes or until tripled in volume. Reduce speed to low, add sugar mixture and beat just until blended, scraping down the side of the bowl. Add lemon juice and beat just until blended. Pour lemon mixture over warm crust and bake for 18 to 20 minutes until filling is just set in the center. Let cool in the pan on a wire rack. Just before serving, lightly sift powdered sugar over the filling and cut into squares.
Note: The recipe can be doubled, but substitute a 13-by-9-inch pan and increase baking time for the filling by about 5 minutes. Also, if you use a glass pan and/or a convection oven, reduce the baking temperature by 25 degrees.
Serves 16