First Step: Prepare Oven and Pastry
Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper. Allow the frozen puff pastry sheet to thaw at room temperature for about 30 minutes until pliable but still cool. If needed, gently roll out the pastry to smooth seams.

Second Step: Make the Cream Cheese Filling
In a bowl, beat cream cheese with 3 tablespoons sugar and vanilla extract until smooth and fluffy using a hand mixer. This mixture will create a luscious, flavorful base inside your danish.

Third Step: Prepare Strawberries
In another bowl, combine sliced strawberries with cornstarch and ½ tablespoon sugar. Let sit briefly to macerate and thicken the juices, preventing your filling from becoming watery.

Fourth Step: Cut and Fill Pastry
Cut the puff pastry into 6 rectangles by halving it lengthwise and then dividing each half into thirds. Score a ¼-inch border around each rectangle without cutting all the way through to create a puffed edge. Spread roughly 1 tablespoon of the cream cheese mixture inside each rectangle, staying within the border. Arrange a compact layer of strawberries on top evenly.

Fifth Step: Apply Egg Wash and Chill
Whisk the egg with water to make an egg wash. Brush the edges of each pastry piece to achieve a shiny, golden hue during baking. Optionally, sprinkle some sugar or demerara sugar on edges for extra crunch. Chill the assembled pastries in the refrigerator for 15-20 minutes to improve puffing.

Final Step: Bake and Glaze
Bake the danishes on the prepared baking sheet at 400°F (204°C) for 20-25 minutes until golden brown and puffed. Remove from oven and cool for 5 minutes on the tray before transferring to a rack. Drizzle lemon icing made from powdered sugar, lemon zest, and lemon juice over the warm danishes just before serving. You can also brush strawberry jam or a vanilla glaze for added sweetness and a glossy finish.