Diabetic Sugarless Banana Bread

1 3/4 c. sifted cake flour
2 tsp. baking powder
1/4 tsp. baking soda
1/2 tsp. salt
1/4 c. melted margarine
2 eggs, beaten
1 tsp. vanilla
2 bananas, mashed
Liquid sweetener to equal 1/2 c. sugar

Sift together flour, baking powder, baking soda and salt. Add remaining ingredients except bananas. Stir only until flour mixture is moistened. Fold in mashed bananas. Pour into greased 8 x 4 inch loaf pan and bake at 350 degrees for about 1 hour or until top springs back.