Preheat oven to 400°.
Boil together water and butter in a medium sauce pan on the stove top.
Remove from heat and stir in 1 cup flour until ball forms.
Add in eggs one at a time, mixing throughly by hand after each. (I use a wooden spoon or my King Arthur bread dough whisk.)
Drop by tablespoonfuls, 3" apart, onto a lightly greased or parchment lined baking sheet.
Bake at 400° for 30 minutes or until puffed and golden brown.
Split cream puffs apart (I use a fork) while hot and remove any soft dough that may be inside.
Cool on a wire rack.
Fill with cream puff shells with lemon cream filling.
Dust with powdered sugar if desired.
Serve immediately or refrigerate.