Preheat the grill or oven to 350°F and lightly grease an 8x8 baking dish.
Separate the crescent dough into individual triangles.
If using frozen peaches, place two slices on the thicker end of each crescent triangle.
If using fresh peaches, use one slice.
Roll the dough around the peaches, folding in the sides as you go they do not have to be completely sealed.
Arrange the dumplings in the prepared baking dish.
In a saucepan, melt the butter, then stir in the brown sugar and cinnamon until fully combined and smooth.
Pour the brown sugar mixture evenly over the dumplings.
Carefully pour the Sprite around the edges of the dish, avoiding pouring directly over the tops so the brown sugar mixture stays in place.
Bake for 30-40 minutes, or until golden brown and bubbly.
Allow to cool slightly before serving.