Haven't yet looked for an actual recipe. (often don't use guidelines for the small experimental batches -- former pastry chef).
BUT I did purchase some excellent dk chocolate with chili (chipoltle?) and roasted pistashios at the Santa Cruz farmer's market a few months ago. It hasn't left my palate memory, yet.
Was thinking about making a small mess,..uh, I mean attempting that (above) but perhaps better (to my palate)...
a tad (1/4 cup or less) of condensed milk (want it rich),
one tablespoon of sweet butter,
heated with (fresh as can be) 3 pinches of chipoltle,
a zest (thin orange skin strip -- no white) or 2 of valencia orange...
then (all) strained...
and tenderly melted with a super dark chocolate
(i.e.: Venchi 85%, 3.52 oz.-- got at Rainbow)...
then adding a mess of freshly roasted pistachios and pouring it to chill (always done best at room temperature -- then chilled if very soft).

My thought is that it may be best to add the spice to the base and not directly to the chocolate..if you want to achieve a fuller range of flavor.
Hope that helps, or at least doesn't confuse more.

just experiment!
good luck,
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