Prehet oven to 325°F. Beat egg whites to solft peaks. Gradually add 1/2 cup sugar and continue beating until egg whites are very stiff. Sift dry ingredients into mixing bowl. Make a well in the dry ingredients and add egg yolks, vegetable oil, mashed bananas, and lemon rind. Beat until smooth. Fold in stiff egg whites.

Bake in an ungreased 10 inch tube pan for 50 to 60 minutes or until a cake tester comes out clean and dry. Remove from oven, invert pan and cool. When cake is cool, remove from pan and dribble glaze over top.