Preheat the oven to 450°.
Line cookie sheets with parchment paper, or grease the cookie sheets.
In a medium saucepan, add in the water and butter and bring it to a boil.
Add in the flour and salt, stirring vigorously with a wooden spoon until the mixture is smooth. (For less vigorous stirring, you can sift in the flour.)
Cool it slightly for 5 minutes.
Add in 4 eggs, one at a time, beating vigorously with a wooden spoon after each egg until the mixture is blended and smooth.
Drop by heaping tablespoons onto the prepared cookie sheets, 2 inches apart.
Bake at 450° for 15 minutes, then reduce the oven to 325° and bake an additional 25 minutes.
Immediately remove the cream puff shells from the cookie sheet onto a wire rack to cool.
With a sharp knife slit each cream puff almost in half.
Fill the cream puff with a filling. I use a Custard Pastry Filling.
Spread chocolate frosting on top of the cream puff or dust the tops with confectioner’s sugar.
Store the cream puffs covered in the refrigerator.