"Я їм канапку на сніданок." should be accepted also. (Never used 'бутерброд' in Ukrainian before.)
A "бутерброд" is a “канапка“ in Ukrainian and it's not a sandwich. It's an open-faced slice of bread, that is a canapé, hence канапка! Ukrainians actually rarely eat sandwiches (two sliced of bread with something between them.