Sour Cream Banana Bread

1/2 c butter
1 c sugar
2 eggs
1 tsp vanilla
1.5 c flour
1 tsp baking soda
1/2 tsp salt
3 mashed ripe bananas (about 1 cup)
1/2 c chopped pecans/walnuts (optional)
1/2 c sour cream

Cream butter and sugar. Add eggs and vanilla. Add dry ingredients (whisked together separately). Stir in bananas, nuts, sour cream. Bake in greased loaf pan at 350 for 1 hour.