Banana Walnut Bread

1 1/2 cups sugar 1/2 cup butter (softened) 2 eggs (beaten) 1/4 tsp. baking powder 1/2 tsp. baking soda 1 1/2 cups flour 3 large bananas that the peel has begun to turn dark (mashed) 1/2 cup walnuts (chopped) 1…