Peel and core apples. Cut each apple into 8 slices each. Roll each apple slice in a crescent roll. Place in a 9 x 13 buttered pan.
Melt butter, then add sugar and barely stir. Add vanilla, stir, and pour entire mixture over apples. Pour Mountain Dew around the edges of the pan. Sprinkle with cinnamon and bake for 40 minutes. Serve with vanilla ice cream, and spoon some of the sweet sauces from the pan over the top.