Preheat the oven to 350°. On a surface dusted with flour, unfold the rolls. Place an apple wedge on the wide edge of each piece of dough. Lightly sprinkle cinnamon, nutmeg, and allspice on apples. Use a pinch of brown sugar on each apple. Roll apple up in crescent roll. Place the dumplings in an 8-inch square baking dish.
Now melt the butter with 3/4 cup of brown sugar and 1/2 tsp. of cinnamon in a saucepan. Stir in the Mountain Dew. Pour the mixture on the dumplings. Cover with foil and bake for 15 minutes. Remove foil and bake 15 more minutes.