• Preheat oven to 375° and line a baking sheet with parchment paper. Set aside.

Blueberry Filling

• In a medium saucepan over low heat, add blueberries, sugar and lemon juice. Stir.
• In a small bowl, mix water and cornstarch together. Mix into blueberries and continue stirring for 3-4 minutes until the sauce thickens up.
• Once the sauce has thickened, remove from heat and let cool.

Cream Cheese Mixture

• In a medium bowl, beat cream cheese until fluffy, about 2-3 minutes.
• Add sugar, egg yolk, and vanilla extract. Beat until combined.

Cut the Pastry Dough

• Gently open up and roll thawed puff pastry a few times until square on a lightly floured surface.
• Spoon half of the cream cheese mixture down the center of each puff pastry leaving about 1½ inch free from filling at each end.
• Once the blueberry mixture has cooled, add half of the blueberry mixture on top of the cream cheese filling, gently spread, then repeat with the other puff pastry.

Cutting the Puff Pastry

• Cut two slits at each end of the pastry about 1 inch long and fold over the top of the filling and secure to prevent mixture from leaking out.
  
• Next cut off the top and bottom side pieces at an angle (see above photo) and continue to make cuts into the pastry along each side making sure not to cut too close to the filling.
• Once the ends have been secured, start folding each piece over each other like a braid and secure.

Egg Wash

• Mix egg and water together
• Brush egg wash over both pastries.
• Sprinkle with coarse sugar.
• Bake in preheated oven for 25-30 minutes or until golden