Heat the oven to 180 C / Gas Mark 4. Grease a 23cm spring-form cake tin and line the base with baking paper.
Melt the chocolate, butter and milk in a large pan over a low heat stirring until smooth.
Remove from the heat, then beat in the sugar and vanilla. Cool slightly.
Beat in the egg yolks and crème fraîche together, then mix this into the chocolate mixture, followed by the flour and baking powder.
Whisk the egg whites in a clean bowl until stiff peaks form. Stir a third of the egg whites into the cake mix, then gently fold in the rest. Pour into the prepared tin and bake for 40-50 minutes until form to touch. Leave to cool for 20 minutes, then remove from the tin and finish cooling on a wire rack.
For the ganache, heat the chocolate and cream together over a low heat until the chocolate has melted. Pour into a clean bowl to cool.
To assemble, slice the cooled cake in half horizontally. Sandwich together with the caramel liquid fudge - you may not need it all. Spread the ganache over the top of the cake, sprinkle with sea salt and chunks of Salted Caramel Fudge.