Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a medium-sized saucepan, combine water and butter. Bring to a simmer over medium heat.
Add flour, stirring constantly until the mixture forms a ball. Remove from heat and let cool slightly.
Add eggs one at a time, beating well between each addition until the batter is smooth.
Pipe or spoon dough onto prepared baking sheet, forming small mounds.
Bake for 25-30 minutes or until golden brown and puffed. Cool on a wire rack.
Whip cream with sugar and vanilla until stiff peaks form. Fill each puff with cream.
Notes
These cream puffs are best served the day they are made. You can store them in the refrigerator for a day or two, but they may lose some of their crispness.