Preheat the oven to 350 degrees.
Combine the cherries, starch or flour, and sugar in a square baking dish.
In a mixing bowl, combine the brown sugar and flour. Add the butter. Using your hands rub the butter into the sugar/flour mix until it's the texture of cornmeal.
Evenly distribute the topping on the cherries. Sprinkle on some demerara sugar on top (optional)
Bake in the oven for 30 to 40 minutes or until the topping has browned and the fruit is thicken. Allow to cool until the fruit sets up before serving. Can be served warm, cold, or at room temperature.