Prepare Pastry Sheet: Unfold the puff pastry sheet. Use a rolling pin to gently flatten it out. Roll a couple of times on each side—don't overdo it.
Fill and Shape: Place the sheet on parchment paper or a silicone mat. Spread half of the cream cheese mixture down the center, leaving about 1 inch at the top and bottom. Add 1 cup of blueberries on top of the filling.
Cut and Fold: Cut two slits on the top and bottom of the pastry from the filling’s edge to the pastry's edge. Fold the top over the filling. Then, cut diagonal slits on each side of the pastry, about 1/2 inch apart. Remove the corners to form a triangle. Fold the strips over the filling, alternating sides to create a braid.
Repeat: Repeat steps 1-3 for the second sheet of puff pastry.