3/4 cup unsalted butter, at room temperature
1/4 cup white sugar
1/2 teaspoon vanilla extract
1 1/2 cups all purpose flour
1/8 teaspoon salt
Cream the butter and sugar until light and fluffy with electric mixer.
Beat in the vanilla extract.
Add the flour and salt and beat until the dough just comes together.
Press onto the bottom of a greased 9x9" pan and bake for about 20 minutes, or until pale golden in colour. Remove from oven and place on a wire rack to cool while you make the filling.