Preheat electric oven to 325°F. Spray a 13 × 9 × 2 inch pan with vegetable oil spray. In a large bowl, using an electric mixer, cream butter and sugar. Add lemon zest and mix well. Add flour and salt and mix until crumbly do not over mix. Press mixture evenly into bottom of prepared pan. Bake for 20 to 30 minutes, or until golden brown.

While crust is baking,combine eggs,sugar and flour into a large bowl. Using an electric mixer mix until just blended. Add lemon juice and mix lightly. Gently stir in lemon zest. Pour over hot crust and bake at 325°F for 20 to 30 minutes, or until feeling is set. Cool,cut into bars and sprinkle with powdered sugar. Makes 24 bars.