Thaw puff pastry sheets at room temperature for 30 to 45 minutes and preheat oven to 400°F (204°C). Line baking sheets with parchment paper.
In a mixing bowl, combine sliced strawberries, sugar, and cornstarch. Mix well and let sit at room temperature for 15 minutes.
In another bowl, beat cream cheese until smooth. Add powdered sugar and vanilla extract, mixing until well combined.
Unfold one puff pastry sheet and cut along fold lines into six smaller rectangles.
Score a ¼-inch border inside the edges of each rectangle without cutting through the dough.
Spread 1 tablespoon of the cream cheese filling inside the border of each rectangle.
Arrange fresh strawberries decoratively over the cream cheese filling.
Brush the edges with egg wash and sprinkle sugar on top if desired.
Chill the prepared danishes in the refrigerator for 15 to 20 minutes if the dough is warm, to help puff pastry rise better.
Bake for 20 to 25 minutes or until golden brown.
Allow danishes to cool for 5 minutes on the baking sheet, then transfer to a rack to cool completely.
Top with warmed strawberry jam or drizzle vanilla glaze made by whisking powdered sugar, milk, and vanilla extract.