3 egg whitesInstructions
Thoroughly mix sugar, flour, salt, and butter. Beat egg yolks; add the milk and sugar mixture. Add lemon juice and rind to the above mixture.
Beat egg whites until stiff but not dry. Fold the whites into the egg yolk and milk mixture.
Pour into an 8-inch-square baking dish and place in a pan of hot water. Bake at 300° to 350° for 45 minutes. Pudding will have a cake-like topping with a creamy lemon custard underneath.