Cream together the butter and sugar until smooth. Add egg and vanilla and mix until incorporated. Careful not to overmix. Add bananas (now you can either lightly mash em and leave chunks, or you can smush them completely so they’re completely incorporated into the cookie. I opted for the former). Mix in the flour and baking soda. Optional: add in the chocolate chips. Spoon onto a parchment paper-lined baking sheet about 2 inches apart and bake for 8-10 minutes (the edges will start to brown and the tops will stop looking so wet). Let cool on a wire rack and OMNOMNOM!