Preheat the oven to 200℃.
Melt the butter over a medium heat. Then pour in the water and bring it to the boil.
Turn it back down to a medium heat, tip the flour in and whilst still over the heat, beat vigorously with a wooden spoon until the dough comes together and it starts to pull away from the sides.
Take it off the heat and set aside for ten minutes to cool down.
Once it has cooled, beat in the eggs one at a time until you have a smooth, thick and glossy mixture.
Grease and line two large baking tins. Use two teaspoons to make small balls, place them onto the baking tins a few cm apart. They will double in size.
Bake them for 18 minutes.
Take them out of the oven, then turn the oven down to 180℃.
Use a knife to cut a small hole in each profiterole, this will let steam escape.Place them back into the oven for a further 5 minutes, until they are golden and crisp.
Transfer them to a cooling rack to cool completely.
Meanwhile, you can make the chantilly cream. Pour the cream into a large mixing bowl along with the vanilla paste and icing sugar. Beat it with an electric whisk until it holds stiff peaks. Be careful not to over whip it.
Place the cream into a piping bag, then once the pastry is cool, poke the nozzle into the slit you made earlier and squirt the cream into the middle.
To Make the chocolate topping, chop the chocolate into small chunks.
Pour the cream into a saucepan and bring to a simmer.
Pour the hot cream over the chopped chocolate and beat with a whisk until smooth.
You can dip each profiterole in the chocolate or drizzle it over, it is up to you.