Prepare the Custard Cream:

• Heat the milk in a saucepan over medium heat until warm but not boiling. Set aside.
• In a bowl, whisk the egg yolks and sugar until pale and creamy.
• Add the flour and mix until smooth.
• Gradually pour in the warm milk, whisking continuously to avoid lumps.
• Return the mixture to the saucepan and cook over low heat, stirring constantly, until it thickens (5-7 minutes).
• Remove from heat, stir in vanilla extract, and transfer to a bowl. Cover with plastic wrap, ensuring it touches the surface, and refrigerate until cooled.

Prepare the Pastry Rolls:

• Preheat your oven to 400°F (200°C).
• Roll out the puff pastry on a floured surface and cut into 1-inch-wide strips.
• Wrap each strip around a metal cannoli tube, overlapping edges slightly to form a spiral.
• Place the wrapped molds on a parchment-lined baking sheet.

Bake the Pastry Rolls:

• Beat the egg and brush it over the pastry rolls for a golden finish.
• Sprinkle sugar over the rolls for extra sweetness.
• Bake for 15-20 minutes, until golden brown and crisp.
• Cool the pastry rolls before carefully removing them from the molds.

Fill the Pastry Rolls:

• Transfer the chilled custard cream to a piping bag with a medium nozzle.
• Pipe the custard into the cooled pastry rolls, filling generously.

Serve and Enjoy:

• Arrange the filled Cannoncini on a serving plate.
• Dust with powdered sugar if desired.
• Serve immediately and savor the heavenly combination of creamy custard and flaky pastry.