This cake is best served gooey in the middle and ever so slightly under-cooked. It is part cake, part brownie and part fondant – basically all of my favourite chocolate desserts rolled into one!
Preheat the oven to 180°C (fan 160°C/350°F/gas 4) and line the baking tin with baking parchment. Melt the butter in a small pan over a low heat or in the microwave. Remove the butter from the heat and add the chocolate. Leave to sit for a couple of minutes and then stir