Preheat oven to 350. Spray 9 in. round pan with vegetable pan
spray. In large bowl, beat butter and granulated sugar until light
and fluffy. Add eggs, vanilla and banana mix well. Combine flour,
baking soda and salt. Add flour mixture and sour cream alternately
to butter mixture. Blend thoroughly but do not over mix.
Prepare icing- in large bowl , beat shortening and butter with
electric mixer until light and fluffy. Add lemon juice and zest;
beat well. Gradually add confectioners' sugar, one cup at a time,
beating well on medium speed and scraping sides and bottom of
bowl often. When all sugar has been mixed in, if icing is dry,
add additional juice and beat at medium speed until light and
fluffy. Keep icing covered with a damp cloth until ready to use.