Peanut butter cookies take 3 ingredients and literally 15 minutes from the moment you decide to make them to the moment you stick the still-too-hot cookie in your mouth.
If cookies are in fact the same as what we call biscuits, you can basically make a crumble mixture (2 parts flour, one part butter, one part sugar, plus any adjuncts you want) then bind it in your hands like you would a snowball, then roll it into a thick sausage, cut quarter-inch-thick discs out of the sausage, and bake them at 160°C for between 15 and 30 minutes depending how good your oven is. They harden as they cool. Easy peasy.