In a large mixing bowl, cream the butter and sugar until light and fluffy. Blend in eggs, bananas, buttermilk, and vanilla. Mix in dry ingredients just until blended, then stir in chocolate chips and nuts, do this by hand. Pour the batter into 2 greased floaf pans Bake in preheated oven at 350* for 45 to 50 minutes until golden brown or until a toothpick inserted in the center comes out clean. Makes and this makes great muffins.