Drain the ricotta in a cheesecloth-lined sieve set over a bowl, refrigerated, for at least 2 hours or overnight, to remove excess whey.

Whisk the drained ricotta with powdered sugar, vanilla, orange zest, and cinnamon if using until smooth. Fold in the chocolate chips. Cover and chill until needed.

Combine the water, butter, sugar, and salt in a 2-quart / 1.9 L saucepan. Bring to a rolling boil over medium heat until the butter melts fully.

Remove from heat, add the flour all at once, and stir vigorously with a wooden spoon until the dough forms a ball and pulls cleanly from the sides.

Return the pan to low heat and stir for 1 to 2 minutes to dry the dough, until a thin film forms on the bottom of the pan. Skipping this step is what makes the puffs turn greasy.

Transfer the dough to a stand mixer bowl, cool for 5 minutes, then beat in the eggs one at a time, fully incorporating each before adding the next, until the dough is smooth, glossy, and falls off the spoon in a slow V shape.

Heat the oil in a 26 cm / 10-inch deep, heavy pot to 175 C / 350 F, checked with a deep-fry or instant-read thermometer.

Working in batches of 4 to 5, drop tablespoon-sized portions of dough into the oil using two spoons or a small ice cream scoop. Fry for 5 to 6 minutes, turning occasionally, until deep golden and puffed and a toothpick inserted comes out clean.

Lift the puffs out with a slotted spoon and drain on a wire rack set over paper towels. Let cool for at least 10 minutes before filling; ricotta melts into a warm shell instead of holding its shape.

Once cooled, cut a small slit into each puff or slice it in half. Pipe or spoon in the ricotta filling generously.

Dust with powdered sugar, top each puff with a piece of candied orange peel and a sprinkle of chopped pistachios. Serve the same day.