Preheat oven to 350 degrees. Spray mini-muffin pans with cooking spray. Stir together the four, baking powder, sugar, salt and nutmeg. Cut in the shortening until the mixture is fine. Add the eggs, milk, apples, and nuts to the dry ingredients. Mix thoroughly. Fill well-greased muffin pans two-thirds full. Bake for 20 - 25 minutes. Remove and roll in the melted butter and then in the cinnamon sugar mixture.