Heat oven to 350°F. Grease and flour 9-inch square pan. In large bowl, combine sugar, 1/2 cup margarine, eggs and banana; beat until light and fluffy. Add milk, sour cream and almond extract; beat until well blended.
Add flour and baking powder; stir just until dry ingredients are moistened. Pour half of batter into greased and floured pan. Sprinkle raspberries over batter. Pour remaining batter over raspberries.
Bake at 350°F. for 50 to 55 minutes or until top is deep golden brown. Cool 20 minutes.
Meanwhile, in small bowl, combine powdered sugar and 1/4 cup margarine; beat until well blended. Add enough lemon juice for desired spreading consistency. Spread over warm cake. Serve warm.