1. Prepare the Puff Pastry

• Thaw puff pastry according to the package instructions.
• Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper.
• Roll out the pastry slightly to smooth creases, then cut each sheet into triangles.

2. Shape and Bake the Croissants

• Roll each triangle from the widest end toward the tip to form crescent shapes.
• Place the croissants on the baking sheet, leaving space between each one.
• Brush lightly with the whisked egg for a golden finish.
• Bake for 15-20 minutes until puffed and golden. Let cool completely.

3. Make the Berry Jam

• In a saucepan, combine blueberries, sugar, and lemon juice.
• Cook over medium heat for 10-15 minutes, stirring occasionally, until thickened.
• Remove from heat and cool completely.

4. Prepare the Cream Filling

• Beat cream cheese, sour cream, and powdered sugar until smooth.
• Add heavy whipping cream and vanilla, then beat on high until stiff peaks form.
• Transfer to a piping bag for easy assembly.

5. Assemble the Croissants

• Slice each croissant horizontally, keeping one side attached to form a pocket.
• Pipe the cream filling into each croissant, then top with a spoonful of berry jam.
• Dust with powdered sugar for a final touch.