Prepare the Danish:

Preheat Oven: Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.

Roll Out Puff Pastry: Unfold the puff pastry sheet onto a lightly floured surface. Cut it into 6 equal squares.

Prepare Cream Cheese Filling: In a medium bowl, mix the softened cream cheese, granulated sugar, and vanilla extract until smooth.

Assemble:

Add Filling: Place about 1 tablespoon of cream cheese mixture into the center of each puff pastry square. Spread slightly, leaving a 1/2-inch border around the edges.

Add Blueberries: Spoon 1 tablespoon of blueberry jam over the cream cheese. Top with a few fresh blueberries, if desired.

Shape and Brush:

Fold Edges: Fold the edges of each square slightly inward to form a border.

Apply Egg Wash: In a small bowl, whisk the egg and milk together. Brush the edges of the puff pastry with the egg wash.

Bake:

Bake Danish: Place the pastries on the prepared baking sheet and bake for 18-20 minutes, or until the pastry is golden and puffed.

Prepare Glaze:

Make the Glaze: In a small bowl, whisk together the powdered sugar, milk (or cream), and vanilla extract until smooth.

Finish:

Drizzle Glaze: Let the danishes cool slightly, then drizzle the glaze over the top.