Preheat the oven to 400ºF. Line a baking sheet with parchment paper or a Silpat.

Cut the puff pastry into six rectangles by following the perforations in the dough to first cut the sheet into three long rectangles and then cut each rectangle in half to form two smaller rectangles. Transfer the pastries onto the baking sheet, arranging them at least 1 inch apart.

Lightly score the dough by cutting a border 1/2-inch from the edges (do not cut through the pastry). Prick the center of the pastry several times with a fork.

In a small bowl, stir together the cream cheese and strawberry jam. Place a dollop of the cream cheese mixture in the centers of each pastry and spread it within the scored area. Top the cream cheese with the sliced strawberries.

Whisk together the egg with 1 Tablespoon water. Brush the edges of the pastry with the eggwash then bake the pastries for 15 to 17 minutes until golden and puffed.

Remove the pastries from the oven oven, dust with powdered sugar (optional) and serve.