In a large bowl, mix the flour, sugar, cocoa powder, and salt together. Cut in the butter until the mixture resembles coarse crumbs. Stir in the egg yolks and wine or vinegar until the dough comes together. Knead the dough on a floured surface for about 5 minutes. Wrap in plastic wrap and refrigerate for at least 1 hour.

Make the Filling

In a medium bowl, combine the ricotta, powdered sugar, vanilla extract, and chocolate chips. Mix until smooth and well combined. Refrigerate until ready to use.

Roll Out the Dough

On a floured surface, roll out the chilled dough to about 1/8 inch thick. Cut out circles using a 4-inch round cutter.

Form the Cannoli Shells

Wrap each dough circle around a cannoli tube, sealing the edges with a bit of water. Repeat until all dough is used.

Fry the Cannoli

In a deep fryer or large pot, heat oil to 350°F (175°C). Carefully lower the cannoli tubes into the hot oil and fry until golden brown, about 2-3 minutes. Remove and drain on paper towels. Let cool slightly before removing the tubes.

Fill the Cannoli

Once the shells have cooled, use a piping bag to fill each shell with the ricotta mixture. Dust with powdered sugar before serving.