Measure flour and set aside. Bring water, butter, vanilla, sugar, and salt to a boil in a 3-qt. saucepan over medium-high heat, stirring occasionally. –
Immediately remove from heat, and quickly stir in flour mixture all at once. Return to heat and stir with a wooden spoon for 1 to 2 minutes, or until dough is smooth and forms a ball
Transfer dough to the bowl of an electric mixer and let cool 5 minutes. Add eggs, 1 at a time, beating until mixture is smooth and glossy.