Crush the walnuts with the back of a spoon until they have been broken into pea-sized pieces. Mix together the peanut and almond butters until smooth and completely combined. Add the peanut flour, oatmeal, milk, stevia, and vanilla extract and stir until a smooth dough forms. It will become very thick so you will eventually have to knead it with your hands. Add the dried cranberries and walnuts and knead into the dough until they're evenly distributed.

Pour the powdered sugar onto a large plate and set it aside. Take roughly 1 tablespoon of the dough and roll it into a smooth ball in the palms of your hands. Then roll it in the powdered sugar until it has a very light coating of the sugar and place it on a separate serving dish. The powdered sugar coating will fade visibly, but the sweetness will remain so not to worry. Repeat this process until all of the dough has been made into truffles. Place the plate of truffles in the refrigerator for 30 minutes to help them stiffen up a bit. Then, enjoy!