I can't seem to find a reference for it, but my memory says that a US Mars Bar had almonds in it. The Wikipedia page[1] seems to indicate as much since it mentions "the American version was discontinued in 2002[10] and was replaced with the slightly different Snickers Almond [...]" Although it lists the contents of the Snickers bar, it doesn't say how it was 'slightly different.'

1 - https://en.wikipedia.org/wiki/Mars_(chocolate_bar)#United_St...