01 - Preheat oven to 400°F and line a baking tray with parchment paper.
02 - In a mixing bowl, blend softened cream cheese, granulated sugar, vanilla extract, and lemon zest until smooth and creamy. Set aside.
03 - In a separate bowl, combine diced strawberries with granulated sugar, lemon juice, and cornstarch. Mix gently and set aside.
04 - Roll out the puff pastry sheet and cut into 8 equal squares. Lightly score a ⅜-inch border around each square without cutting through.
05 - Spread 1 tablespoon of cream cheese filling in the center of each pastry square, staying within the border, then spoon 1 tablespoon of the strawberry filling on top.
06 - Brush the pastry borders with egg wash made by combining the beaten egg and milk.
07 - Bake in the preheated oven for 18 to 22 minutes, or until the pastry is puffed and golden brown.
08 - Transfer the baked pastries to a wire rack to cool slightly.
09 - Whisk powdered sugar, milk, and vanilla extract until a smooth glaze forms. Drizzle over cooled pastries if desired.