Melt 2 tablespoons of butter in a medium skillet on medium heat. Add the apples, 2 tablespoons of sugar, Calvados and cinnamon and cook for 5 minutes, stirring to coat the apples.
Meanwhile, whisk the eggs with 1/2 cup sugar until blended. Sift the flour on top of this and then whisk until blended. Whisk in the melted butter and finally the milk and salt to make a smooth batter.
Place the apples in a greased 1-1/2 quart baking dish. Pour the batter on top. Bake for 25 minutes at 400°F. Serve warm.