Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.

Gently unfold the thawed puff pastry sheet on a lightly floured surface. You can slightly roll it out if needed to create a smooth, even surface. Cut the pastry into four equal squares.

In a small bowl, whisk together the egg and water to create an egg wash.

Place about 2 tablespoons of cherry filling on one half of each pastry square, ensuring you leave a clean border around the edges. This is crucial for a strong seal!

Brush the clear edges of the pastry around the filling with the egg wash. This acts as a powerful glue to prevent any leaks.

Fold the other half of the pastry square over the filling to form a triangle. Gently press down on the edges to seal them together.

Use a fork to firmly crimp all three edges of each hand pie. This creates a strong, decorative seal that completely locks in the filling and prevents leaks during baking.

Place the sealed hand pies on the prepared baking sheet. Brush the tops of the pies generously with the remaining egg wash for a beautiful golden-brown finish.

Make two small slits on the top of each hand pie using a sharp knife. This allows steam to escape safely, preventing the pies from bursting open and letting the filling escape during baking.

Bake for 15-20 minutes, or until the pastries are puffed and golden brown.

Let cool slightly on a wire rack. Dust generously with powdered sugar before serving.