Sandwiches is the English way. In Danish it should be "Sandwicher", but because sandwich is an imported word, many danes just say "Drengene spiser sandwich" it feels more natural to say it that way. But don't worry, if you say "må jeg få to sandwiches", you will get to sandwiches, and no one would lift an eyebrow.
What is the correct pronunciation of the Danish "sandwiches"? I am not sure I am making it out right here at Duolingo. It does not sound like it ends as it is written (i.e., identical to English), rather, it sounds something like "sandwisch", with possibly a stopped syllable at the end.
[I get that both "sandwiches" and "sandwicher" are acceptable usages, I am referring to what I heard said for "sandwiches", in particular]