Spray a 13x9 baking dish or pan. Peel and slice apples into 16 pieces. Roll each apple slice in 1 section of crescent roll. Place rolled slices in pan in two rows, put extras along side. Melt butter, add sugar and cinnamon and pour over apples. Pour can of Mountain Dew over all. Bake at 350 degrees for 45 minutes. Serve warm with vanilla ice cream.