Tart Lemon Squares with Walnut Crust

Love the walnut crust here, you could switch it up with toasted almonds or hazelnuts too.

1 cup all purpose flour
1/4 cup icing sugar
pinch salt
1/2 cup unsalted butter
1/3 cup finely chopped walnuts

Topping:
2 eggs
3/4 cup granulated sugar
1 tbsp finely grated lemon rind
1/4 cup lemon juice
1/4 cup lemon juice
2 tbsp all purpose flour
1/2 tsp baking powder
1 tsp icing sugar

1. In food processor or bowl, blend together flour, icing sugar and salt.  Add butter; pulse or cut in with pastry blender or 2 knives until in fine crumbs.  Stir in walnuts.  Gently press handfuls of dough together; pat into lightly greased 8 inch square cake pan.  Bake in 350 F oven for 20 to 25 minutes or until golden.  Let cool slightly on rack.
2. Topping:  meanwhile, in bowl, beat eggs with sugar until pale and thickened; beat in lemon rind and juice, flour and baking powder.  Pour over base; bake for 25 to 30 minutes longer or until set in centre and golden brown.  Let cool completely on rack.  Dust with icing sugar.  Cut into squares.  

Squares can be covered and refrigerated for up to 4 days.  Makes 20 squares.  About 125 calories per square, 2 g protein, 7 g fat, 15 g carbohydrate.