Roll out the puff pastry to form a square shape then cut into four smaller squares. Transfer to a baking tray then place a few of the blueberries in the centre of each square. Drizzle the honey over the top and a sprinkle of sugar, if desired.
Fold the sides of pastry square over the fruit and seal, turn over and cut two small slits in top. Sprinkle the top with sugar if desired.
Bake in the preheated oven for 30 minutes, or until risen and golden brown. Serve warm from the oven or transfer to a cooling rack to cool completely before enjoying.