
Preheat oven to 350°. In a large bowl, cream butter and 1 cup sugar until light and fluffy, 5-7 minutes. Add eggs, 1 at a time, beating well after each addition. Beat in the bananas, peanut butter, milk and vanilla. Combine the flour, baking soda and salt; add to creamed mixture just until moistened. Fold in chips.
Fill greased or paper-lined miniature muffin cups three-fourths full. Sprinkle with remaining 1 tablespoon sugar. Bake until a toothpick inserted in the center comes out clean, 14-16 minutes. Cool for 5 minutes before removing from pans to wire racks. Serve warm.