Preheat your oven to 425°F (220°C). Line two baking sheets with parchment paper.
In a medium saucepan, combine the water and butter. Over medium heat, stir until the butter melts, and the mixture comes to a boil.
Reduce the heat to low and add the flour and salt all at once. Stir vigorously until the mixture forms a ball and pulls away from the sides of the pan. Remove from heat.
Allow the mixture to cool for about 5 minutes. Then add the eggs, one at a time, mixing well after each addition until fully incorporated.
Transfer the dough to a piping bag fitted with a large round tip. Pipe 1.5-inch circles onto the prepared baking sheets, spacing them about 2 inches apart.
Bake for 20-25 minutes, or until the puffs are golden brown and have puffed up. Avoid opening the oven door during baking!
Once baked, remove the puffs from the oven and let them cool completely on a wire rack.
In a separate bowl, whip the heavy cream with powdered sugar and vanilla extract until soft peaks form.
To fill the cream puffs, use a small knife to cut a slit in the side of each puff and pipe in the whipped cream.
Finally, dust the puffs with powdered sugar before serving.