Step 1: Prepare the Puff Pastry

1. Thaw the Pastry: If using frozen puff pastry, let it thaw according to the package instructions, usually around 30-40 minutes at room temperature.
2. Preheat the Oven: Set your oven to 400°F (200°C). Line a baking sheet with parchment paper.
3. Roll It Out: Lightly flour a clean surface and gently roll out the puff pastry sheet to smooth any creases.

Step 2: Cut the Hearts

1. Create the Heart Shapes: Using a heart-shaped cookie cutter, cut out as many hearts as possible from the rolled-out pastry. Gather the scraps, reroll them, and cut out more hearts.
2. Arrange on a Baking Sheet: Place the hearts onto the lined baking sheet, leaving space between each one.

Step 3: Add a Touch of Sweetness

1. Brush with Egg Wash: In a small bowl, whisk together the egg and water. Lightly brush each pastry heart with the egg wash to give them a golden finish when baked.
2. Sprinkle Sugar: Lightly dust the tops with granulated sugar for a hint of sweetness and extra crispiness.

Step 4: Bake to Perfection

1. Bake the Pastries: Place the baking sheet in the preheated oven and bake for 15-18 minutes, or until the hearts are puffed up and golden brown.
2. Cool Before Serving: Remove from the oven and let them cool on a wire rack for a few minutes.