I ran across two ingredient cookies on Pintester while trying to find something to try out for The Pintester Movement 2.0. God love that woman, She is hilarious.
The cast of characters: Bananas, Oatmeal, Chocolate Chips, Cinnamon, Raisins
Smash up two bananas, add one cup of oatmeal, plus any mix ins you'd like. I made one batch with chocolate chips and one batch with cinnamon and raisins.
Scoop balls of "cookie dough" onto a cookie sheet (you should use a plain greased sheet, the cookies got stuck to the parchment paper)
Bake for 15 minutes.
These cookies tasted alright, but they were missing something... oh yeah, butter sugar, flour, baking soda, and all the other ingredients in a real cookie.