Preheat oven to 350 degrees.
Cream shortening and sugar.
Beat in the eggs vanilla and yogurt.
Crush the bananas. Sift the remaining dry ingredients. Add to batter. Mix in the bananas.
Grease and flour 2 (9-inch by 3-inch) loaf pans.
Bake for 40 to 50 minutes.
A cake tester inserted in center of cake should come out clean.