Toss the apples with 1/2 teaspoon of the cinnamon, 1/2 teaspoon of the nutmeg, and 1 tablespoon of the sugar in a large mixing bowl. In a large ovenproof skillet, combine 1/2 stick of the butter and 1/2 cup of the sugar over medium-high heat. Stir with a wooden spoon until the mixture caramelizes and becomes syrupy.

Spread the apples evenly over the bottom of the skillet and remove from the heat.

Using an electric mixer fitted with a paddle, cream the remaining 1 1/2 cups of sugar and the remaining stick of butter together. Sift the remaining 1 teaspoon of cinnamon, remaining 1/2 teaspoon of nutmeg, baking powder, baking soda, salt and flour together and set aside.

Add the eggs, vanilla and sour cream to the butter mixture. Beat until smooth. Add the sifted flour mixture, a little at a time. Beat until smooth. Pour the batter over the apples in the skillet.

Preheat the oven to 350 degrees F. Bake for about 40 minutes or until golden and the cake pulls away from the sides. Remove from the oven and cool for 15 minutes. Invert the cake onto a platter and serve warm. Garnish with whipped cream.