Papaya Upside-Down Cake

2 cups sliced papaya
2 tablespoons lemon juice
1/3 cup brown sugar
1 tablespoon margarine
1/4 cup shortening
3/4 cup sugar
1 egg
11/4 cups flour
2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup milk
Pour lemon juice over papaya and let stand 15 minutes. Melt
margarine and brown sugar in glass baking dish, 8 x 8 x 2 inches. Place a
layer of papaya slices on top of sugar mixture.
To prepare cake mixture: Cream shortening, add 3/4 cup sugar, and
when well-mixed, add beaten egg. Sift salt, baking powder, and flour
together and add to egg mixture alternately with milk.
Pour batter over sliced papaya and bake in a moderate oven (350ºF)
from 50 to 60 minutes.
When cake is done, turn it upside down on a large plate. Serve hot.