Preheat the oven: Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
Prepare the puff pastry: Roll out the puff pastry sheet on a lightly floured surface to fit your baking sheet. Transfer the rolled-out pastry onto the prepared baking sheet.Slice the puff pastry sheet into three rectangles. Next, gently score the pastry about half an inch from the edges of each rectangle with a knife, ensuring not to cut through the pastry but only to create an outline. Make the cream cheese filling: In a mixing bowl, combine the softened cream cheese, powdered sugar, vanilla extract, and lemon zest (if using). Mix until smooth and well combined. Adjust the sweetness to your liking by adding more powdered sugar if desired.
Spread the cream cheese: Spread the cream cheese evenly over the puff pastry sheet, leaving a small border around the edges.
Add raspberries: Arrange the fresh raspberries over the cream cheese layer. You can place them in a single layer or slightly overlap them, depending on your preference.
Fold the edges: Gently fold the edges of the puff pastry over the filling, creating a border to contain the raspberries and cream cheese.
Brush with egg wash: Lightly brush the edges of the pastry with the beaten egg. This will give the pastry a golden brown color when baked.
Bake: Place the tart in the preheated oven and bake for about 20-25 minutes, or until the pastry is puffed and golden brown.
Cool: Remove the tart from the oven and let it cool slightly on the baking sheet.