Preheat oven to 400 degrees F and line two baking sheets with parchment paper.
In a medium bowl, beat cream cheese, sugar and egg yolk with an electric mixer until smooth.
Roll out puff pastry into a rough 12" by 12" square. Cut in half down the middle and cut each side into 4 pieces. Divide cream cheese mixture between 8 pieces of puff pastry and spread to within 1/2" of the outside.
With a fork, beat egg white and water until combined. Brush around the exposed edges of the puff pastry.
Bake for 15 minutes or until golden brown. Remove from the oven and let cool 20-30 minutes.
Top with a layer of strawberries and brush with jam. Serve immediately.
Cover leftovers loosely with plastic wrap and serve within 6-8 hours.