Fill these too early and you'll have a perfectly good dessert that's stopped being a cannolo -- the shell needs to still be audibly crisp when you bite it, and ricotta sitting inside it for more than an hour or two starts working against that. We fill to order, every time, no exceptions.
Makes about 16.
Combine the flour, sugar, cinnamon, and salt. Cut in the cold butter or lard until the mixture looks like coarse crumbs. Mix in the egg, Marsala, and vinegar, adding a touch more Marsala if needed, until a firm dough comes together. Knead briefly, wrap, and rest for thirty minutes.
Roll the dough as thin as you can manage -- a pasta machine, run through progressively thinner settings, makes this far easier than a rolling pin alone. Cut into circles or ovals about ten centimeters across. Wrap each one around an oiled cannoli tube, sealing the overlapping edge with a dab of beaten egg white.
Fry in batches at 175°C (350°F) until deeply golden and blistered, two to three minutes. Drain, and let them cool for a minute before carefully sliding the shells off the tubes -- attempt this while they're still too hot, and they'll shatter in your hands.
Beat the drained ricotta with the powdered sugar until smooth, and fold in the chocolate chips. Pipe the filling into the cooled shells only when you're ready to serve them, and dip the exposed ends in chopped pistachios.
If the shells come out pale and soft instead of blistered and crisp, either the dough was rolled too thick, or the oil wasn't hot enough to properly puff and color it. If the filling weeps liquid onto the plate, the ricotta wasn't drained thoroughly enough beforehand -- a proper overnight drain in a cheesecloth-lined sieve is worth the wait, and there's no shortcut that replaces it. And if the shells crack apart while you're removing them from the tubes, they were still too hot; give them another minute to firm up before you try.