Roll out pastry in rectangular shape and about 1/8-inch thick, and cut five 5-inch squares.
Place 2 washed, pitted plums in the center of each square and sprinkle each with two tablespoons of sugar.
Wet edges of crust with water or egg white.
Bring corners up to center and pinch edges together firmly.
Place on ungreased shallow baking pan and bake 20 to 25 minutes in a hot oven (425° F.).
Serve warm with sweetened cream and a dash of cinnamon on each.