Join Kim Hammons as she shows you incredibly easy heirloom recipes using American black walnuts. You can get the full recipe online at Hammons Black Walnuts! Wild, natural black walnuts are an American heirloom ingredient, making them the perfect addition to this classic recipe. This is a wonderful dessert for people who prefer desserts that aren't overly sweet. The rich taste and robust crunch tops a bounty of vibrant, sweet-tangy fruit, oats, and buttery brown sugar crumble.