To make the base, mix the gingernuts and sugar in a large bowl and sprinkle in the flaky salt. Pour in the melted butter and mix with a wooden spoon to form a biscuit crumb-like mixture. Press into a 20cm round springform cake tin, spreading the mixture in an even layer to the corners. Chill in the fridge for 30 mins until set.
Put the Christmas pudding, brandy, stout and orange zest in a blender, and whizz to a purée.
Using an electric hand whisk, beat the cream cheese with the double cream, sugar and vanilla seeds, then fold through the purée. Spread the mixture over the biscuit base and leave to chill in the fridge overnight.
The next day, peel the clementines, slice into rounds and place on a baking tray. Sprinkle them with sugar, then blowtorch until caramelised and leave to cool. Release the cheesecake from the tin and arrange the clementines on top. Will keep for three days in the fridge.