Preheat oven to 400 degrees F. Coat a very large baking sheet with cooking spray; place a wire rack over waxed paper, parchment paper, or a large tray. Set aside. In a medium saucepan, combine the water, butter, and salt. Bring to boiling. Add flour all at once, stirring vigorously. Cook and stir until mixture forms a ball. Remove from heat. Cool for 10 minutes. Add eggs, one at a time, beating well with a wooden spoon after each addition.