Preheat an oven to 400°F and line a baking sheet with parchment paper.
In a mixer cream the cream cheese until smooth. Add in the granulated sugar, ½ teaspoon of vanilla extract, flour, 1 egg yolk and the lemon zest. Continue mixing until fully combined.
In a small bowl whisk together the remaining egg and 1 tablespoon of water to make an eggwash. Set aside.
Lay out the puff pastry on a lightly floured surface. Cut each sheet into 6 equally sized rectangles. Score each square leaving an ½-inch border.
Pierce the centers of each rectangle with a fork several times. This helps prevent the puff pastry from rising too much in the centers. Place on a parchment lined baking sheet.
Spoon two tablespoons of the cream cheese filling in the center of each puff pastry rectangle. Top with your desired amount of blueberries.
Brush the edges with the eggwash and bake for 16-18 minutes.
While the danishes are cooling whisk together the powdered sugar, remaining ½ teaspoon of vanilla extract and heavy cream until smooth.
Once the danishes are cool, drizzle with the glaze. Enjoy!