Chocolate Fudge Cake

Sponge

• 200 g unsalted butter, plus extra for greasing
• 200 g dark chocolate, minimum 70% cocoa solids, pieces or callets
• 100 g water
• 250 g self-raising flour
• 25 g cocoa powder
• 180 g light brown sugar
• 180 g golden caster sugar
• 3 large eggs
• 80 g crème fraîche

Icing

• 200 g dark chocolate, minimum 60% cocoa solids, pieces or callets
• 200 g unsalted butter, in pieces, softened
• 200 g icing sugar