In a bowl, beat the eggs, milk and butter. Combine the flour, 1/2 cup sugar, baking powder, 3/4 teaspoon cinnamon, salt and nutmeg; add to the egg mixture and beat just until combined.
Pour into a greased 9-in. round baking pan. Place plums cut side up over batter. Combine remaining sugar and cinnamon; sprinkle over the top. Bake at 375° for 20-25 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes before removing from pan to a wire rack to cool completely. Serve with whipped cream and sprinkle with nutmeg if desired.