Thaw the puff pastry according to package instructions, usually 30-60 minutes at room temperature or overnight in the fridge.

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

In a mixing bowl, beat the cream cheese with white sugar and vanilla extract until smooth. Optionally, add red food coloring and fold in half the diced strawberries.

Roll out the thawed pastry and cut into heart shapes using a heart-shaped cookie cutter.

Spoon or pipe 1-2 tablespoons of the cream cheese mixture into each heart, topping with reserved diced strawberries.

Whisk together the egg and cold water, then brush the mixture over the pastry edges.

Bake in the preheated oven for 12-15 minutes until puffed and golden, rotating halfway through.

Allow to cool on the baking sheet for a few minutes before transferring to a wire rack.