Heat oven to 350 deg. Grease 9 in. pie plate. Place milk, margarine, vanilla, eggs, sugar and Bisquick in blender and blend for 30 seconds. Pour into plate. Bake about 30 min. Arrange bananas on pie. Beat whipping cream and powdered sugar until stiff. Spread over top of pie, covering bananas. Suggestion: Slice bananas after pie is baked and just before covering with whipped cream.)