Make the frosting first. Heat the whipping cream in a heavy-bottom saucepan until it just begins to simmer.
In a bowl put the broken-up pieces of dark chocolate and pour the warm whipping cream over the top.
Allow the cream to melt the chocolate it takes a few minutes them mix until you have a glossy and smooth consistency.
Leave the frosting to cool to room temperature until it is firm enough to scoop with a spoon.
To make the cupcakes preheat the oven to 170℃ (gas 4). Line a muffin tin with the cupcake cases.
In a mixing bowl put the flour, xanthan gum ( if using), cocoa powder, baking powder, baking soda, salt and sugar and mix to combine.
Create a well in the centre and add the oil, eggs and water or milk. Mix together to make a thin batter.
Fill the prepared cake cases with the batter about 2/3 full. I poured mine into a measuring jug as it made it easier to fill the cases.
Bake in the oven for 19 minutes until the cupcake springs back when pressed in the middle.
Now decorate the cupcakes.
Take the cooled frosting and whisk it until it is firm, if it is crumbly or dry add some more cream.
Next either use a piping bag or a spoon to decorate the cakes.
Any leftover cakes that don't have any frosting on can be frozen.