1. Preheat the oven to 450 degree Fahrenheit (230 degrees Celsius), and grease a cookie tray.
2. In a medium saucepan, combine ½ cup butter and 1 cup water. Bring to the boil, stirring until the butter melts completely. Reduce to a low heat, and add the flour and salt. Stir vigorously until the mixture starts to form a stiff ball.
3. Remove from the heat. Add the eggs, one at a time, beating well to incorporate completely after each addition. Using a spoon or a pastry bag fitted with a No. 10 (or larger tip), spoon or pipe the dough onto the cookie sheet in 1 ½ x 4 inch strips.
4. Bake for 15 minutes in the preheated oven, then reduce the heat to 325 degree Fahrenheit (165 degrees Celsius) and bake for 20 minutes longer. Leave to cool completely on a wire rack.
5. For the filling, combine the pudding mix and milk in a medium bowl according to the package direction. In a separate bowl, beat the cream with an electric mixer until a soft peak forms. Beat in ¼ of a cup of confectioner’s sugar and 1 teaspoon of vanilla. Fold the whipped cream into the pudding mixture.
6. Cut the tops off the cooled pastry shells and fill the shells with the pudding mixture. Replace the tops.
7. For the icing, melt the chocolate and 2 tablespoons of butter in a medium saucepan over low heat. Stir in 1 cup of confectioner’s sugar and 1 teaspoon vanilla. Stir in the hot water, one tablespoon at a time, until the icing is smooth and has reached your desired consistency. Remove from the heat, cool slightly, and drizzle over the top of your filled eclairs. Refrigerate until it’s time to serve.