Preheat oven to 375 degree.

Mix cherries, ½ cup granulated sugar and 3 tablespoons of flour in a medium bowl.

Pour into a 9x9 inch baking dish.

In a separate small bowl, combine oats, brown sugar, flour, melted butter, and spice, if using.

Crumble mixture over cherries.

Bake for 30-35 minutes, or until cherries are bubbly and topping is lightly browned.

Serve warm, with or without a scoop of vanilla ice cream.