Preheat Oven:
Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper.
Make Choux Pastry:
In a medium saucepan, combine water, butter, and salt. Bring to a boil over medium heat. Add flour all at once and stir vigorously until mixture forms a ball and pulls away from the sides of the pan. Remove from heat and let cool for 5 minutes.
Add Eggs:
Beat in eggs one at a time, stirring vigorously until fully incorporated. The dough should be smooth and glossy.
Pipe or Scoop Dough:
Transfer dough to a piping bag or use a spoon to drop small mounds (about 1.5–2 inches) onto prepared baking sheet, spaced 2 inches apart.
Bake:
Bake at 425°F (220°C) for 10 minutes, then reduce heat to 350°F (175°C) and bake for an additional 20–25 minutes until puffed and golden brown. Do not open the oven during baking.
Cool:
Remove from oven and let cool completely on a wire rack.
Prepare Filling:
In a chilled bowl, whip heavy cream with powdered sugar and vanilla extract until stiff peaks form.
Fill Cream Puffs:
Slice cooled cream puffs in half or poke a small hole in the bottom and pipe in whipped cream.
Serve:
Dust with powdered sugar or drizzle with melted chocolate, if desired. Serve immediately or chill briefly before serving.