Preheat your oven to 400°F (200°C). Roll out your puff pastry on a floured surface to about 1/8 inch thick, and fit it into a greased 9x9 inch baking dish. Poke holes in the pastry with a fork. Bake for 15-20 minutes until golden brown.

While the pastry cools, combine 2 cups of milk, 1/2 cup of sugar, and 1 tablespoon of vanilla extract in a bowl. Whisk until sugar is dissolved. Add 3 room-temperature eggs and blend until incorporated.

Transfer the custard mixture into a saucepan and heat over medium, stirring constantly for about 10-12 minutes until it thickens.

Remove from heat and let the custard sit for about 5 minutes. Whisk vigorously for 1-2 minutes until smooth and glossy.

Pour the smooth custard over the cooled puff pastry, spreading evenly. Let it rest for a few minutes.

Whip 1 cup of heavy cream until soft peaks form. Spread the whipped cream over the custard layer.

Cover with plastic wrap and chill in the refrigerator for at least 4 hours, preferably overnight.