Combine crumbs and butter; press into pan, building up the sides. To make filling: Beat cream cheese until fluffy. Gradually blend in 1 cup sugar, lemon juice, 1 teaspoon vanilla and salt. Add eggs, one at a time, beating well after each. Pour filling into crumb crust. Bake at 325° for 30 minutes, or until set.

Topping: Combine sour cream, 4 tablespoons sugar and 1 teaspoon vanilla. Spoon over top of pie. Bake 10 minutes longer at 325°. Cool, then refrigerate several hours before serving. Half of this amount fits a 9-inch pan.