Preheat oven to 400 °F (200 °C) and line a baking sheet with parchment paper.

Roll out the thawed puff pastry sheet on a lightly floured surface to smooth seams. Cut into four equal rectangles (~3×6 inches each).

In a small bowl, beat the softened cream cheese, sugar, and vanilla extract until smooth and creamy.

Spread about 2 tablespoons of the cream cheese mixture onto each rectangle, leaving a narrow border around the edges.

Sprinkle mini chocolate chips (or chopped chocolate) evenly over the cream cheese layer.

Fold the long edges inward toward the center, slightly overlapping, to encase the filling and create a Danish shape. Press edges gently to seal.

In a small bowl, whisk together the egg yolk and water. Brush the pastry edges lightly with egg wash for a golden finish.

Transfer the Danish pastries to the prepared baking sheet. Bake for 15–18 minutes, or until puffed and golden brown.

Remove from the oven and let pastries cool on the baking sheet for a few minutes before transferring to a wire rack.