Preheat oven to 375. Grease a 13x9x2" baking dish.
Peel and core the apples and cut each into 8 slices. Roll each slice individually in a crescent roll. Place in prepared well greased baking dish.
Melt butter. When melted, remove from heat stir in sugar and vanilla. You do not want the sugar to dissolve. Spoon over crescent rolls to cover. Sprinkle with cinnamon. Pour the can of Mountain Dew around the rolls. Bake at 375 until apples are tender...approximately 45 minutes. Enjoy!