In a large bowl, whisk the flour, sugar, and salt together. Rub in the lard with your fingertips until the mixture looks crumbly.

Add the egg and chilled wine, mixing into a shaggy dough. Knead on a floured surface for 5 minutes until smooth. Wrap and rest at room temperature for 30 minutes.

Whisk the drained ricotta with the sugar, cinnamon, and vanilla until smooth with no visible grains. Fold in the chopped chocolate and chill until you're ready to fill.

Divide the rested dough in two. Roll each half on a floured surface to about 2 mm thickness. Cut rounds with a 12 cm / 4.7-inch cutter, rerolling scraps once.

Place a heaping tablespoon of filling off-center on each round. Fold the dough over into a half-moon, press the edges to seal, then crimp with a fork dipped in flour.

Keep shaped cassatelle covered on a floured tray while you finish the batch, so the dough doesn't dry out.

Heat the oil in a 24 cm / 9.5-inch deep pot to 170 C / 340 F, checking with a deep-fry thermometer.

Fry the cassatelle in batches of 4 to 5, don't crowd the pot, for 2 to 3 minutes per side until blistered and deep golden.

Lift out with a slotted spoon onto a paper towel-lined tray to drain.

Let cool for 5 minutes, then dust generously with powdered sugar. Serve warm or at room temperature.