Boil blueberries, water add 1/2 cup sugar in a saucepan until there is plenty of juice. Sift together flour, baking powder, salt, 1 teaspoon sugar and cinnamon. Cut in 1 tablespoon butter. Add milk to make soft dough, like biscuit dough. Drop by spoonfuls into stewed blueberries. When the dumplings are fluffy, serve hot with cream.