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

Roll out the puff pastry on a floured surface, and using a heart-shaped cookie cutter, cut out heart shapes.

Place the hearts on the lined baking sheet and brush each one with the egg wash for a shiny finish.

Bake for 12-15 minutes, or until the pastries are golden brown and puffed up. Once done, let them cool on a wire rack.

Heat the milk in a saucepan over medium heat until it begins to steam but does not boil.

In a bowl, whisk together the egg yolks, sugar, cornstarch, and vanilla until well combined.

Gradually mix the warm milk into the yolk mixture, whisking continuously to prevent any curdling.

Return the mixture to the saucepan and cook over medium heat, stirring often until thickened. Remove from heat and let cool slightly.

In a small saucepan, combine the cherries, sugar, lemon juice, water, and cornstarch. Cook over medium heat, stirring until the mixture thickens and the cherries soften (about 5-7 minutes).

Once the pastries have cooled, generously spoon the creamy custard onto each heart and top with the cherry mixture. If desired, brush with apricot jam or honey for a glossy finish.