Rhubarb Upside-down Cake

Topping:

3 cups sliced fresh rhubarb
1 cup granulated sugar
2 Tablespoon all-purpose flour
¼ teaspoon ground nutmeg
¼ cup butter or margarine, melted
Sprinkle rhubarb in a greased 10-inch cast iron skillet.  Combine sugar, flour and nutmeg; sprinkle over rhubarb. Drizzle with butter.

Batter:

1 ½ cups all-purpose flour
¾ cup granulated sugar
2 teaspoons baking powder
¼ teaspoon salt
½ teaspoon ground nutmeg
¼ cup butter or margarine, melted
2/3 cup milk
1 egg

Whipped topping (optional)

Combine flour, sugar, baking powder, salt and nutmeg in a mixing bowl.  Add butter, milk and egg; beat until smooth.  Spread over rhubarb mixture.  Bake at 350 degrees for 35 minutes or until the cake tests done.  Loosen edges immediately and invert onto serving dish. 

Serve warm, topped with whipped topping if desired.