Raspberry Lemonade Bars Ingredients for the crust: 8 tablespoons unsalted butter (1 stick), at room temperature 1/4 cup sugar 1 cup unbleached all-purpose flour pinch salt for the filling: 1 1/2 cups sugar 3 egg whites 1 whole egg 2/3 cup freshly squeezed lemon juice (from 3 lemons) 2 tablespoons lemon zest (from 2