°Heat oven to 375° degrees, with rack in center.
° Thoroughly mix brown sugar, 1 1/2 tablespoons flour, 1/4 teaspoon cinnamon, ground ginger, and candied ginger. Add to plums an dmix well. Arrange, skin side up, in ungreased, deep 9-inch pie plate.
°Combine remaining sugar, baking powder, flour, cinnamon, and salt. Mix well. Stir in egg. Then, using hands, mix thoroughly to produce little particles. Sprinkle over plums.
°Drizzle butter evenly over crumb mixture and bake for 30 to 35 minutes. The crumble is done when the top is browned and plums yield easily when pricked. Remove from oven and cool.
°Serve warm or refrigerate for up to two days or freeze well covered.