Preheat the oven to 400°F (200°C).

In a saucepan, combine water and butter; bring to a boil.

Add flour and salt all at once; stir vigorously until the mixture forms a ball.

Remove from heat and let cool slightly. Add eggs one at a time, mixing well after each addition.

Transfer the mixture to a piping bag and pipe small mounds onto a baking sheet.

Bake for 20-25 minutes until golden and puffed. Let cool.

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

Gradually add powdered sugar and vanilla extract; continue whipping until stiff peaks form.

Transfer the whipped cream to a piping bag.

Once the choux pastry shells are cool, cut a small hole in the bottom of each.

Pipe the cream filling into each shell until filled.

Serve immediately or refrigerate until ready to serve.