1. Preheat oven to 400°F (200°C). Line 2 baking sheets with parchment.

2. Make the filling: In a small saucepan, combine blueberries, sugar, lemon juice, zest, and a pinch of salt. Cook over medium heat 3–5 min until juicy. Stir in cornstarch slurry; simmer 1–2 min until thick and glossy. Cool completely.

3. On a lightly floured surface, roll pastry to ~1/8 in (3 mm) if needed. Use a ghost cookie cutter (or knife + template) to cut pairs of shapes; re-roll scraps.

4. Arrange half the ghosts (bottoms) on the sheets. Spoon ~1–2 tsp cooled filling in the center, leaving a 1 cm border.

5. Brush edges with plant milk. Cover with top ghosts; press to seal and crimp with a fork. Cut a tiny steam vent (mouth) or two small slits for eyes.

6. Brush tops with plant milk; sprinkle coarse sugar if using. Chill 10 minutes on the tray for best puff.

7. Bake 15–20 minutes until puffed and deep golden. Cool 10 minutes.

8. Icing: Whisk powdered sugar, lemon juice, and plant milk to a thick drizzle. Spoon or brush over warm pies. Add eyes (choc chips, piped chocolate, or sesame). Let set before serving.