Preheat oven to 450F, grease a big baking sheet.
In a saucepan combine water and butter, bring to a boil and stir so the butter fully melts. Turn heat down, add flour and salt. When it thickens remove it from the heat.
Add eggs one by one, mixing well. Pipe onto baking sheet in 1.5x4" strips. Makes about twelve, and fits on a single big sheet.
Bake 15min at 450F, then turn heat down to 325F for another 20min. They're done when they feel light, airy, and sound hollow when tapped on the bottom. Let them cool on a rack.
After they've cooled, cut in half horizontally and fill with a bit under one recipe worth of pastry cream. Then pipe a strip of one recipe worth of chocolate icing along the tops.
Chill before serving.