Preheat oven to 350 degrees. In a large mixing bowl mix skim milk, egg, and butter(if using) together, add in flour, peanut butter, peanuts, and sugar and mix into a thick batter.

Scoop heaving tablespoons of batter onto a greased baking pan, or cookie sheet, seperated 2-3 inches apart. For the traditional peanut butter cookie design, lay a fork parallel with cookies and press down, then turn fork 90 degress and press down again, to make a criss cross pattern.

Place cookies in the oven, preheated to 350 degrees, and bake for 10-12 minutes. Allow to cool after baking until stable enough to remove yet still warm.