Start with Valrhona chocolate, spike it with chiles, or top it with a homemade marshmallow; whatever your mood, there's a hot chocolate waiting for you in Boston. Boston.com has assembled 15 favorites, from the L.A. Burdick concoction that begins with a combination of ground chocolate and cocoa (see the Roadfood.com review of the New Hampshire flagship), to the hot chocolate flight of three drinks at Finale Desserterie.