1. Preparing the Puff Pastry:

1. If using store-bought puff pastry, allow it to thaw according to package instructions.

2. Roll out each pastry sheet on a lightly floured surface to ensure even thickness.

3. Use a fork to poke small holes across the dough to prevent excessive puffing.

4. Transfer the pastry onto a lined baking sheet. Place another sheet of parchment paper and a second baking tray on top to keep the layers flat and crisp while baking.

5. Bake at 375°F (190°C) for 15-20 minutes, or until golden brown and flaky.

6. Pro Tip: For extra-crispy layers, bake the sheets one at a time instead of stacking them in the oven.

2. Making the Pastry Cream:

1. In a saucepan over medium heat, warm the milk until it starts to steam but does not boil.

2. In a separate bowl, whisk together the egg yolks, sugar, cornstarch, and vanilla extract until smooth.

3. Slowly pour the warm milk into the egg mixture, whisking constantly to prevent curdling.

4. Return everything to the saucepan and cook over low heat, stirring continuously until thickened (about 5 minutes).

5. Remove from heat and allow the pastry cream to cool completely before using.

3. Assembling the Milhojas:

1. Place the first puff pastry sheet on a serving plate.

2. Spread an even layer of pastry cream or dulce de leche over the pastry.

3. Repeat with another pastry layer and more filling.

4. Top with the final puff pastry sheet, pressing gently to secure the layers.

4. Caramelizing the Top Layer:

1. Sprinkle granulated sugar evenly over the top pastry layer.

2. Use a kitchen torch to caramelize the sugar until it melts and forms a golden crust.

3. Let the caramelized layer set completely before slicing.