The thickness and bitterness of your drink
will depend on your chocolate’s level of cacao, which varies among brands. We got great results with Ghirardelli, which produced a full-bodied cocoa (our preference for dunking the ginger doughnuts
). We also used Lindt to good effect, but needed to add more cornstarch for extra thickening. Chocolate with more than 60 percent cacao will be too bitter.