1. In a mixing bowl combine flour, sugar and salt.
2. Add the melted butter and marsala wine.
3. Turn out onto a lightly floured surface and knead until well mixed.
4. Wrap dough in plastic wrap and refrigerate for 2 to 3 hours.
5. Roll out the dough until very thin.
6. Using a cookie cutter or the rim of a glass, cut dough into 4-inch rounds, and roll again until very thin.
7. Roll each piece tightly around a cannoli tube.
8. Seal with egg white.
9. Heat the vegetable oil in a deep 3.5 quart pot to 350 degrees.
10. Place the dough forms in the hot oil and fry until golden brown, 2-3 minutes.
11. Place on paper towels to drain.
12. Cool and gently twist tube to remove shell from form.
13. Place the dough forms in the hot oil and fry until golden brown, 2-3 minutes.
14. Place on paper towels to drain.
15. Cool and gently twist tube to remove shell from form.
16. In a large mixing bowl whip sugar, vanilla and ricotta together until smooth, then stir in the chocolate chips.
17. Spoon filling into a pastry bag with a large round tip.
18. Pipe the ricotta cream into the pastry shells, dust with confectioners sugar and serve immediately.