Fudge Cake Custard

From the 1941 cook book again. Haven't tried yet. She says that baked they will have custard on bottom and sponge cake on top. I don't know how many this makes, so I'm guessing 3.

• Ready In: 1 hr
• Serves: 3

Ingredients

• 1  tablespoon butter
• 6  tablespoons sugar
• 2  tablespoons flour
• 1  pinch salt
• 1  melted  chocolate square
• 1  egg
• 1  cup milk

Directions

1. Beat egg white until stiff.
2. Cream butter and sugar.
3. Add flour and salt.
4. Add cooled melted chocolate.
5. Add egg yolk and milk.
6. Gently fold egg white in mixture.
7. Spoon mixture into buttered individual custard cups.
8. Set cups into pan of water.
9. Bake 30 to 35 minutes in moderate oven or until done.