In a mixing bowl. cream together the butter or margarine and sugars. Beat for 2-3 minutes. Add the vanilla and eggs and beat an additional 2 minutes. Add the mashed banana, just until combined.
In a small bowl. whisk together the flour, baking soda, baking powder, salt, cinnamon and nutmeg. Add to the mixing and stir just until moistened.
By hand, stir in the oats, chocolate chips and raisins.
Place heaping tablespoons of dough on an ungreased cookie sheet and bake at 350 degrees for 15-18 minutes.
Notes
*Feel free to play around with the chocolate chips and raisins. Use 2 cups of one and omit the other, omit them both all together, add some nuts in place of one or some…basically, do what you want. Enjoy!