Preheat the oven to 425°F (220°C) and line a baking sheet with parchment paper.

In a saucepan, bring the water and butter to a full boil. Add the flour all at once and stir vigorously until a smooth dough forms and pulls away from the sides of the pan.

Continue cooking the dough for 30–60 seconds until a thin film forms on the bottom of the pan.

Transfer the dough to a bowl and let it cool slightly.

Add the eggs one at a time, mixing well after each addition, until the dough is smooth and falls from a spoon in a slow ribbon.

Pipe or spoon small mounds onto the prepared baking sheet, spacing them apart.

Bake for 20–25 minutes until puffed and deeply golden. Do not open the oven early.

Turn off the oven, poke a small hole in each shell, and return them to the warm oven for 5 minutes to dry. Cool completely.

Whip the cream with powdered sugar and vanilla until soft peaks form. Fill the cooled profiteroles.

Heat the cream for the chocolate sauce until just steaming, pour over chopped chocolate, and stir until smooth. Drizzle over filled profiteroles before serving.