Pastry: Put butter and water in small saucepan; stir over high heat until melted and liquid is boiling rapidly. Add flour and salt at once; raise saucepan a few inches above heat. Stir briskly. Mixture will come away from sides of pan and form a ball in center.
Cook and stir 30 seconds more. Remove from heat. Break 1 egg into the paste; beat fast until smooth and fluffy. Repeat until all the eggs are used.
Drop by whatever size you want (1/4 cup) onto ungreased cookie sheet 3 inches apart. Bake at 350 degrees until puffed and golden 35-40 minutes. Cool away from drafts. Cut off tops and fill with filling or ice cream.