Preheat the oven to 300° F. Line two baking sheets with parchment paper. Remove the logs of dough from the refrigerator and slice into 1/2 inch thick rounds. Arrange on the baking sheets, keeping at least an inch between each cookie. Place the cookies in the oven and bake for about 15-20 minutes, or until golden, rotating the pans halfway through. Transfer the baking sheets to a wire rack to cool. Dust with powdered sugar, and serve! Cookies can be stored at room temperature in an airtight container for up to a week. Any extra dough can be frozen for up to a month.