Special equipment: cannoli molds; a pastry bag
For the shells: Sift the flour, granulated sugar and salt into a medium bowl. Work the butter pieces in with your fingers. Then add the egg yolk. Work in the white wine until a smooth dough forms. Wrap the dough in plastic and let rest for a few minutes while you make the filling.
For the filling: Sift the powdered sugar, allspice and ginger into a medium bowl. In another medium bowl, whisk the ricotta until smooth and then add it to the dry ingredients; mix to blend. Beat the cream until fairly stiff and gently fold it into the ricotta mixture with a rubber spatula. Stir in the chocolate chips. Lightly zest the lemon and stir it into the ricotta. Refrigerate.
To roll and fry the shells: Heat the oil to 350 degrees F in a heavy-bottomed medium pot. Meanwhile, spread an even layer of flour on a flat surface and flour a rolling pin. Roll the dough until very thin (about 1/8-inch thick). Cut out 3- to 4-inch rounds, using a glass or a small bowl; you should have about 12 rounds. Wrap each one around a cannoli mold, pressing to enclose. Flare the edges out slightly from the mold. Use a pair of tongs to submerge the shell in the hot oil. Fry until crispy, 2 to 3 minutes. Remove from the oil and immediately slide the shell off the mold. Set aside to cool. Repeat for all the rounds.
To fill the cannoli: Just before serving, use a pastry bag to pipe the ricotta filling into the cannoli shells. Fill the shells from both sides so that the cream fills the length of the shell. Sprinkle the sesame seeds generously onto the ricotta on each end. Dust with powdered sugar. Serve immediately.
If the ricotta has excess liquid, place it in a strainer and allow to drain for at least 30 minutes before making the filling.