Make the Blueberry Filling – Heat blueberries, sugar, lemon zest, cornstarch, and water in a saucepan. Simmer for 3–5 minutes until thickened. Cool.
Prepare the Cream Cheese Filling – Beat together cream cheese, sugar, lemon juice, lemon zest, and vanilla extract until smooth.
Preheat Oven & Prepare Pastry – Set oven to 375°F (190°C). Roll out puff pastry and cut into 4-inch squares.
Shape & Fill – Fold pastry edges slightly to form a diamond shape. Add 1 tbsp lemon cream cheese filling and 1 tsp blueberry filling in the center.
Egg Wash & Bake – Brush edges with egg wash, sprinkle with sugar, and bake for 15–18 minutes until golden.
Make Lemon Glaze – Mix powdered sugar, lemon juice, and vanilla extract.
Drizzle & Garnish – Drizzle over warm pastries and top with fresh blueberries and lemon zest.
Serve & Enjoy! – Best served warm or at room temperature.