[QUOTE=PastAllReason]
They are flavoured hot chocolate mixes rather than simply cocoa powder. At least north of the 49th parallel you can buy all kinds of flavours: truffle, kahlua, amaretto, raspberry chocolate, mint chocolate, etc. I often buy some single serving sizes (they come in pouches) to use as stocking stuffers at Christmas. Can you not buy these in the US?
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I can resoundingly answer, Yes! I don’t know about individual packets, but definitely tins.
Back to the OP: I am almost completely clueless when it comes to culinary history, but my WAG would be that drinking chocolate declined when the even stronger buzz of coffee became widely known.