Preheat the oven to 210°C.
Cut the butter into small pieces.
Place the water, salt and butter in a saucepan and bring to the boil. Once boiling, remove from the heat and mix in the sifted flour. Return to the heat and mix until the mixture no longer sticks to the bottom of the pan. Transfer to a food processor and beat in the eggs one by one. The mixture should be shiny and smooth and have a dropping consistency. Place the mixture into a piping bag and pipe small profiteroles on to a baking tray. Bake for 10-15 minutes.
Split the vanilla pod and grate. Boil the milk with the vanilla pod and coffee.
Break the eggs into a bowl and add the sugar. Whisk energetically for one minute before adding the flour. Next, add the hot milk, mix again and then return to the pan. Bring back to the boil and cook for 3 minutes whisking continuously.Transfer the crème pâtissière onto a tray, cover with cling film to prevent it from drying and set aside in the fridge.
Once the crème pâtissière is cool, whisk the double cream until it has the texture of chantilly cream and then fold into the cold crème pâtissière. Fill a piping bag with this mixture.
Pierce a small hole in the base of each profiterole and fill with the crème pâtissière.
Slightly warm the fondant icing and stir the coffee flavouring. Dip the top side of the profiterole into the coffee icing and allow to set.
«To make eclairs use the same choux pastry mix and pipe 5 cm by 1.5 cm lengths.»