Sweetened condensed milk
Beat egg yolks and combine with condensed milk. Add lemon rind, juice, vanilla and nutmeg. Blend well.
Fold in stiffly beaten egg whites. Set aside. Combine melted butter and zweiback crumbs. Sprinkle butter 8-inch square or 9-inch round cake pan with half the crumbs. Pour in reserved filling mixture and sprinkle with remaining crumbs. Bake at 325 F ofr 30 minutes.
Turn off heat;let cool for one hour in oven with door closed. Makes 8 servings.