So what is a bread sandwich?
The argument is this - are three pieces of bread stacked on top of one another a sandwich or not? Some say it is a bread sandwich while some say it is not, since bread can not be a "filler".
There is a toast sandwich, which, according to Wikipedia, is "a sandwich made by putting a thin slice of toast between two thin slices of bread with a layer of butter, and adding salt and pepper to taste." It can be traced back to as early as 1861. This, however, brings up another point of debate. Since the bread in the center is different, is it any more or less of a sandwich? Some critics say that if the bread in the center is toasted or a different type of bread from the other two, it is a sandwich while if all three are the same, it is not.
An image of a toast sandwich, shot from the side, 2014. Photo by Ryan North.