Preheat your oven to 400°F (200°C). On a lightly floured surface, roll the pastry slightly to even it out.

Place the rolled pastry onto parchment-lined baking sheets. Prick all over with a fork to prevent puffing, then cover with another layer of parchment and place a baking sheet on top to keep it flat.

Bake for about 15–20 minutes, or until golden and crisp. Once baked, allow it to cool completely. Trim the pastry into three equal rectangles.

In a saucepan, heat the whole milk and vanilla extract until just simmering.

In a bowl, whisk the egg yolks, granulated sugar, and cornstarch until smooth.

Gradually add the hot milk to the egg mixture while whisking continuously to prevent curdling.

Pour everything back into the saucepan and cook over medium heat, stirring constantly until thickened.

Remove from heat and stir in the unsalted butter.

Transfer your pastry cream into a bowl and cover it with plastic wrap directly on the surface to prevent a skin from forming. Chill in the refrigerator until cold.

To assemble, place one puff pastry rectangle on a serving plate.

Spread half of the chilled pastry cream over it, add the second pastry layer, and top with the remaining cream. Finally, add the last pastry layer on top.

For the glaze, mix the powdered sugar with water until you achieve a smooth consistency, then spread it over the top layer.

To decorate, drizzle melted chocolate and lightly drag a toothpick through the chocolate to create beautiful patterns.

Chill the assembled dessert for at least 1 hour before slicing.