I do these kinds of cookies on occasion! :) You can do anything with them! I don't add the tbsp of water and flour tho...just a stick of butter and egg.
Ambrosia cookies are great! Orange cake mix, butter, egg, crushed pineapple (well drained), coconut, pecans or walnuts...
Rocky Road cookies have mini marshmallows and walnuts added in...
Low fat Apple Spice cookies have applesauce instead of butter, and 2 egg whites instead of the whole egg...sometimes I add grated apple, and nuts.
The combinations are endless!