1. Preheat oven to 350 degrees.
2. In a large bowl, cream together the butter, brown sugar and white sugar until light and fluffy. Add the eggs one at a time, beating well with eaceh addition, then stir in the vanilla, banana, and peanutbutter.
3. Combine the flour, baking powder, baking soda and salt; gradually stir into the creamed mixture. Stir in the rolled oats and chocolate chips. Drop by rounded spoonfuls on ungreased sheet.
4. Bake for 12-14 minutes.