Preheat the oven to 350°F and line a baking sheet with parchment paper.
In a bowl, mix softened cream cheese, egg yolk, sugar, and vanilla until well combined.
Roll out the thawed puff pastry and cut out heart shapes with a cookie cutter.
Use a knife to score around the edges of each heart.
Place the hearts on the baking sheet and fill each one with the cream cheese filling, then top with diced strawberries.
Brush the edges with egg wash and bake for 23-25 minutes until golden brown.
Dust with powdered sugar if desired and enjoy warm or at room temperature.