1. Preheat the oven to 400°F (200°C).
2. Roll out the puff pastry and cut it into strips about 1 inch wide.
3. Wrap each strip around a metal cone mold, slightly overlapping as you go.
4. Brush the wrapped pastry with egg wash for a golden finish.
5. Sprinkle sugar over the pastry for added sweetness and crunch.
6. Place the wrapped molds on a baking sheet lined with parchment paper.
7. Bake for 15-20 minutes until golden brown and crispy.
8. While the pastry bakes, prepare the pastry cream by heating milk in a saucepan.
9. In a separate bowl, whisk egg yolks, sugar, and cornstarch until smooth.
10. Slowly pour the hot milk into the egg mixture, whisking continuously.
11. Return the mixture to the saucepan and cook over low heat until thickened.
12. Remove the pastry cream from heat and add vanilla for flavor.
13. Let the pastry cream cool completely before using.
14. Once the pastry shells are baked, let them cool slightly.
15. Carefully remove the metal molds from the cooled pastry.
16. Fill a piping bag with the cooled pastry cream.
17. Pipe the pastry cream into each cannoncino just before serving.
18. Optionally, dust the filled cannoncini with powdered sugar.
19. Serve immediately for the best texture and flavor.
20. Enjoy your homemade Italian cream-filled cannoncini!