... or Sandwiches
Some places I'm getting Sandwiche, some places Sandwiches... Even Butterbrote (pl. lit. Butter Bread) is also used..
"Butterbrot", "belegtes Brot"; I would say that the difference here is that you think of dark bread and not of white bread.
Sandwichs, Sandwiche, Sandwiches
They all seem to be correct.