Combine pecans 1/4 cup sugar and cinnamon stir well and set aside. Cream shortening and 1 cup sugar until light and fluffy. Add eggs beating well after each addition.
Add flour alternately with the sour cream then stir in the vanilla and bananas just enough to blend.
Sprinkle half of reserved cinnamon mixture into bottom of a well greased Bundt pan; spoon half of the batter into pan. Sprinkle remaining cinnamon mixture over batter, then spoon balance of batter into pan. Bake at 350 degrees for 40-45 minutes or until tests done. Cool coffee cake 5 minutes in pan on a wire rack. Serve warm or cold.