In a large bowl, using an electric mixer, beat the egg whites with the salt at high speed until soft peaks form. Beat in the granulated sugar, 1 tablespoon at a time, until the whites are stiff. Using a rubber spatula, fold in the ground nuts. Spread the batter on the parchment in a 9-by-12-inch rectangle. Bake for 20 minutes, until golden. Prop the oven door open and let the dacquoise sit for 1 hour.