Ingredients
1 1/2 cups all purpose flour
1/4 cup powdered sugar
pinch of salt
1/2 cup (1 stick) chilled unsalted butter, cut into pieces
1/2 teaspoon vanilla extract
Topping:
5 large eggs room temperature
2 cups sugar
1 cup strained fresh lemon juice
3 tablespoons all purpose flour
2 1/2 tablespoons grated lemon peel
Preparation
For crust:
Position rack in center of oven and preheat to 350 degrees. Line 9 inch square baking pan with 2 inch high sides with foil, extending 1 inch above 2 sides of pan. Butter 2 uncovered sides of pan. Combine flour, powdered sugar and salt in processor. Add butter and cut in using on/off turns until mixture appears sandy. Add vanilla and process until dough begins to come together. Press dough evenly into prepared baking pan. Bake crust until golden brown about 28 minutes.
Mean while prepare topping:
Whisk eggs and 2 cups sugar in a medium bowl to blend. Whisk in lemon juice, then all purpose flour. Strain into another bowl. Mix in grated lemon peel.
Reduce oven temperature to 325 degrees. Pour filling over hot crust. Bake until sides are set and filling no longer moves in center when pan is shaken, about 22 minutes. Cool on rack. Cover and chill at least 4 hours or overnight.
Using foil sides as aid, lift dessert from pan. Fold down foil sides. Cut into 16 squares.
