You can buy black walnuts in many supermarkets. Or you can use regular walnuts, but they are not as good as the wild ones for this kind of recipe. Using cake flour improves the texture of these cookies, but you can certainly use all-purpose; my mum does.
2sticks of butter(1/4 pound), cut into small pieces
Powdered sugar for dusting,about 1 cup
Instructions
Preheat the oven to 350°F. Mix all the ingredients except the powdered sugar in a large bowl. Mix with your clean hands, mashing the dry ingredients with the butter until you get a mixture that looks like lumpy meal.
Form the dough into little balls the size of a walnut and place on an ungreased sheet pan. Bake for 18 minutes. Take the cookies out and let them cool for 5 minutes or so. After they are cool enough to handle but still warm, roll them in the powdered sugar and set aside on a rack to cool. Then, when they are totally cool, roll them in powdered sugar one more time.