The old fashioned chocolate eclair recipe given below comes from America's most famous cooking school of the nineteenth century, The School of Cooking in Boston. It does require a little preparation time, but it's an easy recipe to make, and the eclairs taste absolutely delicious.
I can't recall Mom making these eclairs too often because they can be a wee bit finicky to fill, but when she did they were a surefire hit with everyone. By the way, she also used the same yummy chocolate eclair frosting on her homemade brownies.
Miss Parloa's New Cook Book (1880)
Don't you love biting into a freshly made eclair? Just thinking about
it, I can almost taste the soft shell with its creamy filling and rich
chocolate frosting. Enjoy learning how to make homemade eclairs from
scratch that'll turn out just like Mom's while using the same chocolate eclair recipe that she used.
Put one cupful of boiling water and half a cupful of butter in a large saucepan, and when it boils up, turn in one pint of flour. Beat well with the vegetable masher. When perfectly smooth, and velvety to the touch, remove from the fire.
Break five eggs into a bowl. When the paste is nearly cold, beat the eggs into it with the hand. Only a small part of the eggs should be added at a time.
When the mixture is thoroughly beaten (it will take about twenty minutes by hand), spread on buttered sheets in oblong pieces about four inches long and one and a half inches wide. These must be about two inches apart.
Bake in a rather quick oven for about twenty-five minutes. As soon as they are done, ice with chocolate frosting. When the icing is cold, you will cut the eclairs on one side and fill them.
Put one cupful and a half of milk in the double boiler. Beat together two-thirds of a cupful of sugar, one-fourth of a cupful of flour, two eggs, and one-fourth of a teaspoonful of salt. Stir the mixture into the boiling milk. Cook fifteen minutes, stirring often. When cold, flavor with one teaspoonful of vanilla extract.
Put two squares of scraped chocolate with five tablespoonfuls of powdered sugar and three of boiling water. Stir over the fire until smooth and glossy. Dip the tops of the eclairs in this as they come from the oven.
When the chocolate icing is dry, cut open, and fill with the cream, which should be cold. If a chocolate flavor is liked with the cream, one tablespoonful of the dissolved chocolate may be added to it.