Place butter, water and salt in a saucepan and bring to a boil. As soon as it comes to a boil, add the flour, remove from heat and beat well till the mixture leaves the sides of the pan.
When cool enough to touch, beat in the eggs with an electric beater (a little at a time, if not using an electric beater), till the mixture is light and fluffy.
Rinse a plastic bag (or icing bag) with water. Fill the bag with the egg and flour mixture and snip a 3/4"-1" hole in one corner.
Take an un-greased baking tray and pipe out straight lines of about 3" length, spaced an inch part.
Bake in a pre-heated oven for 30-40 minutes (they stop making a faint sizzling sound). Remove from oven and pierce on the side with a knife and leave to cool. They would sink if not pierced.
Whip cream, sugar, vanilla and rum together till thick enough to be piped out.
Mix icing ingredients together over low heat, till well blended and smooth.
When puff cases are cool, snip a cut into the top half, enough for an icing nozzle to be pushed in to fill the cream in.
Slit the eclairs horizontally half way, till just short of the edge, so they stay joined. Pipe the cream into the cases with and icing gun or polythene bag.
Coat the exposed part with the icing, and serve.
Key Ingredients: Chocolate, butter, salt, all purpose flour, egg, cream, sugar, vanilla essence, rum, cocoa, icing sugar