Method:

1). Put the 80g butter, 25g white sugar and 0.5tsp salt for the profiteroles in a wide-bottomed pot with 250ml of water and bring to a simmer.
2). Add the sifted flour and stir for a good 5 minutes over a low to medium heat, until the paste comes away from the pot.
3). Transfer this immediately to a food mixer or processor with a beater attachment. Add the 4 eggs, one by one, and beat to a smooth, shiny stiff paste. (If the mixture is too wet, there is a risk that the profiteroles will collapse during baking. Add a pinch more flour if the mixture isn't the right consistency). Put this in a bowl, cover with tin foil and leave to cool.
4). Preheat the oven to 180 degrees Celsius. Spoon the choux paste into a piping bag with a plain nozzle (or ziplock bag with the one corner cut open) and pipe 2.5cm blobs (in a circular motion) on to a baking tin. Each one should stand up nice and high, and you should get roughly 20 profiteroles in total. Bake for about 18 to 20 minutes until golden in colour. Do not take the profiteroles out of the oven too early - there is a great risk of them collapsing if the outer-shell hasn't hardened sufficiently yet. Err on the side of longer cooking time.
4). Working quickly, pierce each one to let out the steam and cool on a wire rack before filling.
5). In the interim, to make the crème Chantilly, add the vanilla seeds, scraped from the pod, to the whipping cream along with the caster sugar and 0.5tsp vanilla extract and whip until firm.
6). Pipe into the cooled choux buns (again using a piping or ziplock bag).
7). To make the chocolate sauce, put the 50g butter, double cream, 100g of coconut blossom sugar and 1tsp vanilla extract into a wide-bottomed pot and bring to a simmer.
8). Add the cocoa powder and whisk while continuing to cook for 5 minutes at a slow simmer.
9). Remove from heat and add the dark chocolate, stirring until the chocolate has melted. Pass the sauce through a fine sieve if lumps remain.
10). Drizzle the choux buns with warm chocolate sauce.