Black walnut trees used to grow wild along the fencerows bordering many Amish farms. The wood from these trees is now in such high demand that comparatively few of them remain. Despite the fact that the nuts were difficult to shell and stained the hands of the sheller with a black, acidic liquid, the nuts were freely harvested and mixed into cakes and pies. Their flavor is strong and penetrating, so only a relative few are needed to enliven the taste of the dessert of which they are a part. This is a rich dish for special times.