Mix cherries, sugar, water, and cinnamon together in a saucepan; bring to a boil.

Mix flour, baking powder, and salt in a bowl. Gradually stir milk into flour mixture until incorporated; drop by spoonful into the boiling cherries.

Place a cover on the saucepan, reduce heat to medium-low, and cook at a low boil for 25 minutes. Remove the cover and cook until the flour mixture is cooked through, about 10 minutes more.