Preheat the oven to 400°F (200°C).

In a saucepan, combine water and butter over medium heat until the butter melts.

Add the flour and salt all at once, stirring vigorously until the mixture forms a ball and pulls away from the sides of the pan.

Remove from heat and let cool for 5 minutes.

Add the beaten eggs one at a time, mixing well after each addition until the dough is smooth and glossy.

Transfer the dough to a piping bag and pipe small mounds onto a baking sheet lined with parchment paper.

Bake for 20-25 minutes until puffed and golden brown. Do not open the oven door during baking.

Remove from the oven and let cool completely.

In a mixing bowl, whip the chilled heavy cream until soft peaks form.

Add powdered sugar and vanilla extract, and continue to whip until stiff peaks form.

Transfer the whipped cream to a piping bag.

Once the choux pastry shells are cool, use a sharp knife to make a small hole in the bottom of each puff.

Pipe the whipped cream filling into each puff until filled.

Serve immediately or refrigerate until ready to serve.