To be honest, the cream’s a bit much. But apart from that, lovely! So, first make the chocolate sauce:
Put 200g dark chocolate (broken into pieces), 100ml double cream, 100ml whole milk and 3 tablespoons of golden syrup into a pan. Warm gently until all of the ingredients have melted, then pour the sauce into smallish cups and leave it to cool.
Meanwhile, make the churros. Put 250ml water, 120g butter and a pinch of salt into a medium-sized pan. Bring to the boil, then whisk in 130g strong white bread flour, half a teaspoon of baking powder and a few drops of vanilla essence. It will become unfeasibly thick but try to keep beating it over a low heat for a few more seconds. Take the pan off the heat and beat in an egg, and then a second egg. It should look a bit less worrying now. Cover the mixture and leave at room temperature for 15 minutes to a couple of hours.
When you are ready to cook, put sunflower oil into a large frying pan. It should be 2-3cm deep. Heat it to maximum. Put the churros mix into a large piping bag with a star nozzle. When the oil is very hot, squeeze in lots of chipolata-sized churros, snipping or cutting them each time from the nozzle. Be careful! Turn them after a couple of minutes to cook the other side. Place a large colander over an even larger pan. With a slotted spoon, fish out the churros and place them into the colander as they turn golden-brown. Once you have them all in there, shake the colander carefully to remove the oil, then sprinkle over some golden caster sugar and give them another shake.