01 - Preheat oven to 400°F (200°C) and line a baking tray with parchment paper.
02 - Combine cream cheese, granulated sugar, vanilla extract, and lemon zest in a bowl. Whisk until smooth and creamy. Set aside.
03 - In a separate bowl, toss diced strawberries with granulated sugar, lemon juice, and cornstarch until evenly coated.
04 - Roll out puff pastry sheet and cut into 8 equal squares. Score a ½-inch border around each square without cutting through the dough.
05 - Spoon 1 tablespoon of cream cheese filling into the center of each pastry square and gently spread within the scored border.
06 - Spoon 1 tablespoon of strawberry filling on top of the cream cheese in each square.
07 - Brush the edges of each pastry square with egg wash made from the beaten egg mixed with milk.
08 - Transfer to the oven and bake for 18 to 22 minutes until pastry is puffed and golden brown.
09 - Remove from oven and allow to cool slightly on a wire rack.
10 - Whisk powdered sugar, milk, and vanilla extract together until smooth. Drizzle glaze over cooled pastries if desired.