Put the butter in a saucepan with boiling water.
Place over heat and bring to a boil.
Boil until butter is thoroughly melted.
Add flour all at once and stir vigorously.
Cook until mixture is thick and smooth and does not stick to side of pan, stirring constantly so that it will not burn.
Remove from heat and cool slightly.
Add eggs, one at a time, beating in each egg thoroughly, until the mixture is smooth, before adding the next one.
Beat mixture well.
To make Cream Puffs drop by spoonfuls on a greased baking sheet 1 1/2 in. apart and shape round with the handle of a spoon.
To make Eclairs, put the paste in a pastry bag and force through a round tube 1/2 in. in diameter for small 6clairs, and 1 in. in diameter for large ones, making them 3 1/2 to 4 in. long.
Bake either Cream Puffs or Eclairs in a hot oven of 400Â° F. for 35 min.
To fill: Allow the Cream Puffs or Eclairs to cool thoroughly.
Cut a slit in the side of each and put filling in with a spoon, or insert the end of a pastry tube and force the filling in.
Use sweetened and flavored whipped cream, custard, or ice cream to fill the shells.
Frost with a thin uncooked icing or serve with crushed berries chocolate or caramel sauce.