Knoppers is a product that is structurally strikingly similar to Hanuta, which is an acronym for HaselNussTasche. Directly, it translates to hazelnut pocket, but it's more like 2 wholegrain waffles (a thin, fine and crispy kind) sandwiching a layer of chocolate with pieces of nut between them. Knoppers additionally has a creme layer reminiscent of Oreo creme.
I hope this was American enough to understand.