1/2 cup butter, cubed
1 cup water
1 cup all-purpose flour
1/4 teaspoon salt
400ml cups milk
3 egg yolks
4tbsp plain flour
1 teaspoon vanilla extract
1 cup heavy whipping cream
60g semisweet chocolate
2 tablespoons butter
1 cup icing sugar or to taste
2 to 3 tablespoons hot water
(I used only melted semi sweet chocolate in melted butter mixed avoiding extra sugar)
In a large saucepan, combine butter and water. Bring to a rapid boil, stirring until the butter melts. Reduce heat to low; add flour and salt. Stir vigorously until mixture leaves the sides of the pan and forms a stiff ball. Remove from the heat. Add eggs, one at a time, beating well after each addition.
With a tablespoon, spoon in the mixture in a shape you like or with a pastry tube fitting with a no. 10 or larger tip pipe dough into 4-in.-long x 1-1/2-in.-wide strips on a greased baking sheet.
Bake at 450°F (230C)for 15 minutes. Reduce heat to 325°F(160C) bake 20 minutes longer. Cool on a wire rack.
For filling, in a large bowl, whisk milk little milk with egg yonks, sugar and flour. Add remaining milk and stir under low heat on a stove until the mixture is starchy. Remove from heat and add vanilla essence. slice the cooled puffs and fill with cream.
In another large bowl, whip cream until soft peaks form. Beat in sugar and vanilla. Fill cooled shells on top of the cream mixture.
For icing, melt chocolate and butter in a small saucepan over low heat. Stir in sugar. Add hot water until icing is smooth and reaches desired consistency. Cool slightly. Spread over eclairs. Chill Eclairs until serving.