In a large mixing bowl, whisk together the Dr. Pepper soda, milk, and dry pudding mix powder until blended and thickened, about 2 minutes.
Fold the whipped topping into the pudding mixture with a rubber spatula, ensuring it is thoroughly combined and no streaks of pudding remain.
Pour the pie filling into a graham cracker crust.
Freeze the pie uncovered for minimum of 4 hours, or overnight, before cutting into slices and serving.
Serve with whipped cream and cherries on top.
