01 - Preheat oven to 400°F and line a baking tray with parchment paper.
02 - In a small bowl, thoroughly combine cream cheese, granulated sugar, vanilla extract, and lemon zest until smooth and creamy. Set aside.
03 - In a separate bowl, toss diced strawberries with sugar, lemon juice, and cornstarch until the fruit is evenly coated. Set aside.
04 - Unfold puff pastry and roll out gently if needed. Cut into 8 even squares. Score a half-inch border around each square without slicing all the way through.
05 - Spoon 1 tablespoon cream cheese filling into the center of each pastry square and gently spread within the scored border.
06 - Spoon 1 tablespoon strawberry mixture over the cream cheese layer on each square.
07 - In a small bowl, beat egg with milk. Brush the borders of each pastry square with the egg wash using a pastry brush.
08 - Place pastries on the prepared tray and bake for 18 to 22 minutes, or until golden and puffed.
09 - Transfer pastries to a wire rack to cool slightly.
10 - For the glaze, whisk together powdered sugar, milk (add milk gradually for desired consistency), and vanilla extract until smooth. Drizzle over cooled pastries if desired.