1 box sour cream cake mix
2 eggs
1 teaspoon baking soda
1/2 cup buttermilk, sour cream or yogurt (add 1/2 tsp. lemon juice to milk if you don't have these)
1 c. mashed ripe bananas
1/2 c. chopped nuts
1 tsp. vanilla

Mix cake according to instructions on box but add these additional ingredients during preparation. Bake in preheated oven at 350 degrees for 25 minutes or until tooth pick inserted in center is nearly clean. Cake will spring back slightly when touched.