Banana Bars

2 cups sifted flour
2 tsp. baking powder
1/2 tsp. salt
1/4 cup shortening
1/2 tsp. vanilla
1 cup sugar
2 eggs
1 cup mashed bananas
1/2 tsp. lemon extract
1/2 cup chopped nuts

Sift flour, baking powder and salt. Cream shortening and sugar, add eggs, beat well. Add flour to creamed mixture, with bananas. Add flavoring and nuts. Spread batter in 8 x 13 inch pan. Bake 350 degrees for 30 minutes. Frost while warm with powdered sugar icing. When cool, cut into bars or squares.