• Preheat the oven to 400F.
• Line 2 baking sheets with parchment paper and set aside.
• Cut pastry into 3 strips along fold marks. Place on a baking sheet and poke a few holes in the each pastry with a fork. Bake for 15 minutes or until golden. Remove from baking sheets and let them cool on a rack.

Make the Cream:

• In a medium saucepan place the milk and bring to a simmer. Meanwhile, in a small bowl stir together the sugar, cornstarch and salt.
• Gradually add the cornstarch mixture to the milk and cook stirring often about 6 minutes or until thickens. Whisk in the yolks and cook for about 2 minutes more stirring often.
• Stir in the butter and vanilla extract and remove from the heat.
• Let it cool at room temperature, cover and refrigerate until ready to use.

Assemble:

• Using a fork, split each pastry into 2 layers. Spread pastry cream on 1 pastry layer. Repeat layers. Top with arequipe or dulce de leche.