Preheat oven to 350 degrees. Butter a 13×9 inch baking dish. Peel and core apples, cut into 8 wedges. Roll each apple piece in a crescent roll and place in prepared dish. Melt butter in a saucepan and add sugar, vanilla and cinnamon. cook on low until thickened. Pour over dumplings. Carefully pour the soda into the middle and sides of a pan, avoiding onto rolls. Bake for 45 minutes, or until golden brown.