I wonder why PB cookies are marked with a criss cross pattern. Here is the answer from Wikipedia - The Peanut Butter Balls recipe in the 1931 edition of Pillsbury's Balanced Recipes contains the first known written instance of instructing the cook to press the cookies using fork tines. The recipe does not explain why this advice is given, though: peanut butter cookie dough is dense, and without being pressed, it will not cook evenly. Using fork tines to press the dough is a convenience.
So there you are... the criss cross pattern being carved painstakingly on each tiny cookie. But the end result looks fun doesn't it? I hope you like this prep board. Available at Etsy soon.