Place the puff pastry on the counter for 30 minutes to thaw until pliable but still cool.

Meanwhile, make the ganache: pour chocolate chips into a bowl, heat the cream until steaming, and pour it over the chocolate. Let sit for 1½ minutes, then stir until smooth. Microwave in 15-second bursts if needed. Leave at room temperature for 2 hours until thickened to a pudding-like texture.

Beat cream cheese until smooth, then add sugar and vanilla. Mix until creamy.

On a lightly floured surface, unfold pastry sheets and press seams together. Cut into 12 rectangles. Whisk the egg and water, then brush along the edges of each rectangle.

Preheat oven to 400°F. Line two cookie sheets with parchment. Place six rectangles on each sheet. Score a smaller rectangle inside each piece, leaving a ½-inch border, and spread 1 tablespoon cream cheese filling inside.

Chill one tray in the fridge and the other in the freezer for 5 minutes. Bake one tray at a time for 17–20 minutes until puffed and golden. Cool completely.

Spoon ganache over the cream cheese centers, leaving the edges exposed.