Preheat your oven to 400°F (200°C).

On a lightly floured surface, lay out the puff pastry sheets and cut them into squares or rectangles.

Arrange the cut pastry on a lined baking sheet. Bake for about 15-20 minutes, or until puffed and golden brown. Let cool on a wire rack.

In a saucepan over medium heat, combine milk, eggs, sugar, and vanilla extract. Whisk constantly until thickened, about 5-7 minutes. Remove from heat and let cool slightly.

Once cool, slice the pastry layers in half. Layer with custard filling and top with another layer of pastry.

Dust with powdered sugar and add fresh berries on top. Serve immediately or refrigerate for later.