1. Prepare the Crust:

1. Preheat oven to 375°F (190°C) and grease a muffin tin.
2. In a saucepan, bring butter and water to a boil over medium heat.
3. Remove from heat and quickly stir in flour, salt, and sugar until a smooth dough forms.
4. Return to low heat and cook, stirring constantly, for 1-2 minutes until dough pulls away from the sides.
5. Remove from heat and let cool slightly. Beat in eggs one at a time until fully incorporated and dough is glossy.
6. Spoon dough into prepared muffin tin, filling each cup about 2/3 full.
7. Bake for 25-30 minutes until puffed and golden brown. Do not open oven during baking.
8. Remove from oven and let cool slightly before serving.