Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper.
Beat the softened cream cheese, sugar, and vanilla extract until smooth.
Wash, dry, and thinly slice the strawberries. Toss them gently with the flour.
Place the thawed puff pastry on a lightly floured surface and cut it into 6 squares.
Transfer the pastry squares to the prepared baking sheet.
Spoon a small amount of cream cheese filling into the center of each pastry.
Arrange strawberry slices over the cream cheese.
Leave the pastries open-faced or fold the corners toward the center.
Whisk the egg and water together and brush the exposed pastry edges with the egg wash.
Sprinkle with coarse sugar if desired.
Bake for 18–22 minutes, until puffed and golden brown.
Cool for several minutes, then dust with powdered sugar and serve.
