Besides being simple and inviting, one of the things that makes this cake “rustic” is the way the ingredients are chopped. The coarsely chopped, unpeeled apples and the coarsely chopped walnuts aren’t refined in their size or in the chopping technique. But, honestly, it is one of the things that I think make this cake so good! You know when your are eating an apple; you can see it and taste it.