Preheat your oven to 400 degrees and spray a 9 by 13 inch baking dish with cooking spray.
Combine the apple slices, 1 teaspoon cinnamon, and 1/4 cup granulated white sugar in a large bowl. Set asside.
Pour the 1/2 cup melted butter into the baking dish.
In a large bowl, whisk together 1 cup sugar, 1 cup flour, 2 teaspoons baking powder, and 1/4 teaspoon salt. Whisk in 1 cup milk and 2 teaspoons vanilla extract. Pour the mixture over the butter without stirring together.
Pour the apple mixture over the batter without stirring it together. Bake for 20 to 25 minutes or until the edges are golden brown. Serve warm with ice cream and the caramel sauce.