Ingredients
1 quart plum filling
1 quart brown sugar
2 cups flour
1 quart oats, rolled
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon salt
1 tablespoon cinnamon
1 pound margarine, softened

Directions
Mix all ingredients, except plum filling, to form a crumbly top.  Press half of mixture into two 12x20x2 stem table pans.  Spread plum filling evenly over crumb mixture.  (Drained plum slices placed in an overlapping position can be used.)  Sprinkle remaining crumb mixture on top.  Bake in 400 f oven for 25 minutes or until top is crisp and golden brown.