Created by Derf on November 19, 2011
Step 1: Preheat oven to 350f degrees. In a large bowl, cream together sugar, margarine and egg yolks until fluffy. Combine flour with baking powder. Beat into egg mixture alternately with milk. Beat egg whites until stiff but not dry. Fold into batter. Pour batter into greased 9 inch square cake pan.
Step 2: Half and pit the plums; arrange on top of the batter. Streusel topping: In a small bowl, combine brown sugar, margarine and cinnamon. Sprinkle over fruit. Bake in 350°F degree oven, on the middle rack for 35-45 minutes or until top is golden and tester inserted into centre of cake comes out clean. Cool or serve warm.
Step 3: Glaze (optional) Combine icing sugar, milk and vanilla. Drizzle over cooled cake.