Yummy Lemon Bars

These bars were featured on Martha Stewart and very delicious. I brought them to Kristen's baby shower! Enjoy!

for Crust:
3/4 cup flour
1/3 cup powder sugar
1/4 cup cornstarch
1/4 t. salt
1/2 cup butter

for filling:
4 eggs
1 cup sugar
2/3 cup fresh lemon juice
1/4 cup flour
1/2 t. baking powder
1/2 t. salt
Preheat oven to 350. Spray a 9 inch square pan with cooking spray. Make the crust: mix flour, sugar, cornstarch and salt. Cut butter in to form coarse crumbles. Press mixture into pan. Refrigerate 15 minutes. Bake until crust is lightly browned 20 minutes. Let cool. Reduce the oven temp to 325. Beat eggs with mixer until thick. Beat in sugar, lemon juice, flour, baking powder and salt. Pour over crust. Bake until set about 20-30 minutes. Cool. Refrigerate about 1 hour. Sprinkle with powder sugar.