Combine prunes and brown sugar.
Spoon into 11 1/2x7 1/2x1 1/2 inch baking dish.
Sift together dry ingredients; add egg, tossing with fork till mixture is crumbly; sprinkle evenly over plums.
Drizzle with butter.
Bake in moderate oven (375Â°) about 45 minutes or till lightly browned.
Serve warm topped with ice cream or whipped cream