Preparation

Preheat egg to 350 degrees and set up for indirect cook. Line an 8 inch square

baking pan with heavy duty aluminum foil, extending it 2 inches beyond the sides

(to create a handle, so that the bars can easily be lifted out of the pan). Spray the

bottom and sides of the foil with Pam or other nonstick spray.

To make the crust, combine the 2/3 cup of flour, the vanilla wafer crumbs, the sugar

and butter in a medium bowl, stirring until the mixture is crumbly. Press into the

bottom of the pan to form an even crust. Bake until firm, about 10-12 minutes.

Meanwhile, whisk together the 1 cup sugar and 2 tbsp. flour. Whisk in eggs, egg

whites, lemon zest, lemon juice and lime juice until well blended. Pour over hot crust

and return pan to the egg and bake until golden and set in the center, about 30

minutes. Cool completely in the pan on a rack. Lift out the whole thing and place on

a cutting board. Remove foil and cut into 16 squares. Sift confectioners' sugar on

top (if using).