Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper.
In a saucepan, combine butter, water, sugar, and salt. Bring to a boil over medium heat.
Remove from heat and stir in flour all at once. Return to heat and stir vigorously for 2–3 minutes until dough pulls away from sides and forms a ball.
Transfer dough to a mixing bowl and let cool for 5 minutes. Add eggs one at a time, beating well after each until smooth and glossy.
Transfer dough to a piping bag fitted with a large round tip. Pipe 4–5 inch long strips onto prepared baking sheet.
Bake for 10 minutes at 425°F, then reduce oven to 375°F (190°C) and bake for 20–25 minutes until golden and puffed. Cool completely on a wire rack.