Step 1: Preheat the Oven and Prepare Your Baking Sheet

Begin by preheating your oven to 400°F (200°C). Line a large baking sheet with parchment paper or a silicone baking mat to prevent the pastries from sticking. This will also make cleanup much easier.

Step 2: Prepare the Cream Cheese Filling

In a medium mixing bowl, combine the softened cream cheese, granulated sugar, and vanilla extract. Using a hand mixer or a spatula, mix until smooth and creamy. Set the cream cheese filling aside while you work on the blueberries.

Step 3: Prepare the Blueberry Mixture

In a small bowl, toss the blueberries with the lemon zest and cornstarch. The cornstarch helps thicken the blueberry juices as they bake, preventing them from becoming too watery and seeping out of the pastry. The lemon zest adds a bright, citrusy flavor that complements the sweetness of the blueberries.

Step 4: Roll Out the Puff Pastry

Lightly flour your work surface and gently unfold one sheet of thawed puff pastry. Using a rolling pin, roll it out slightly to smooth the creases and make it just a bit thinner. You want the pastry to be about 1/8-inch thick. Repeat with the second sheet of puff pastry.

Step 5: Cut the Puff Pastry into Squares

Once the puff pastry is rolled out, use a sharp knife or a pizza cutter to divide each sheet into 6 equal squares. You should end up with 12 squares in total, which will be the base of your pastries.

Step 6: Add the Filling

Place about 1 tablespoon of the cream cheese mixture in the center of each puff pastry square. Spread it out slightly, but leave a small border around the edges to prevent the filling from leaking out. Next, add a heaping teaspoon of blueberries on top of the cream cheese mixture.

Step 7: Fold the Pastry

For each square, gently fold two opposite corners of the pastry over the filling, overlapping them slightly in the center. Press the seams together gently to secure them. Don’t worry if the filling isn’t completely covered—some of it peeking out adds to the charm of the pastry.

Step 8: Brush with Egg Wash

In a small bowl, lightly beat the egg to create the egg wash. Using a pastry brush, lightly brush the tops of the pastries with the egg wash. This will help them turn a beautiful golden brown as they bake.

Step 9: Bake the Pastries

Transfer the pastries to the prepared baking sheet, making sure to leave a bit of space between them so they can puff up. Place the baking sheet in the preheated oven and bake for 18-20 minutes, or until the pastries are golden brown and flaky. Keep an eye on them toward the end of the baking time to ensure they don’t overbake.

Step 10: Let Cool and Add Glaze

Once the pastries are done baking, remove them from the oven and transfer them to a wire rack to cool slightly. While the pastries are cooling, whisk together the powdered sugar, milk, and vanilla extract in a small bowl to create the glaze.

Drizzle the glaze over the slightly warm pastries for a sweet finish. If you prefer, you can also dust them with powdered sugar instead of glazing them.

Step 11: Serve and Enjoy

Your Blueberry Cream Cheese Puff Pastries are now ready to serve! Enjoy them warm or at room temperature with a cup of coffee or tea, or as part of a brunch spread.