When I want a little sweet treat I make smoothies.
My base is always frozen banana + milk + oats then do one of these:
Cinnamon + vanilla
Pumpkin + pumpkin spice+ brown sugar
Strawberries/blue berries
Cost like under a dollar to make a good cup and they are pretty filling.
Which is probably even more unhealthy than regular coke since it uses the same or more amount of sugar but artificial sugar.