Preheat the oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking pan
Cut each apple into 8 wedges and set aside. Separate the crescent roll dough into triangles. Roll each apple wedge in crescent roll dough starting at the smallest end. Pinch to seal and place in the baking dish.
Melt butter in a small saucepan and stir in the sugar and cinnamon. Pour over the apple dumplings. Pour Mountain Dew TM over the dumplings.
Bake for 35-40 minutes in a preheated oven, or until golden brown. Serve with french vanilla ice cream if desired.