1/4 cup butter or margarine
1/2 cup peanut butter
1/2 cup sugar
1 tsp vanilla
2 eggs
2 cups flour
1 tsp salt
1 tsp baking soda
1 cup mashed bananas, about 3 medium
3/4 cup mini-chocolate chips

Preheat oven to 350°F. In a large bowl, cream together the first four ingredients, until fluffy. Beat in the eggs, one at a time. In a separate bowl, combine together the flour, salt and baking soda. Alternately add and blend into the larger bowl, portions of the dry ingredients and the mashed bananas. Fold in the chocolate chips. Spoon the batter into well greased muffin tins. Bake for 25 minutes, then cool on a wire rack.