Chocolate parkin with marbled custard

Method

1. To make the spiced vanilla cream, heat the double cream in a pan with the whole spices and vanilla. As soon as it begins to simmer, remove from the heat, cover, then leave to infuse for at least two hours (ideally overnight in the fridge). Strain before using.
2. Heat the oven to 150°C fan/gas 3½. Grease the cake tin with butter and line with baking paper. Put the 100g butter, treacle, golden syrup and muscovado sugar in a saucepan over a low heat, stir until melted, then remove from the heat and leave to cool.
3. Put the flour, cocoa powder, ground spices, bicarbonate of soda and oats in a large bowl and stir to combine. Make a well in the centre, then stir in the slightly cooled treacle mixture, followed by the egg, then the milk (bit by bit to avoid lumps). Pour the mixture into the prepared tin, then bake for about 50 minutes until a knife or skewer pushed into the centre comes out clean.
4. To make the chocolate custard, heat the milk and cream together until almost boiling. Whisk the egg yolks in a bowl with the sugar, cocoa and cornflour, then pour a little of the hot milk and cream over the top. Whisk well, then pour in the rest of the cream mixture and whisk again to combine. Return to a clean pan and cook over a low-medium heat, stirring constantly, until it forms a custard that thickly coats the back of a wooden spoon. Roughly chop the stem ginger and stir into the custard.
5. To serve, cut the parkin into 9 squares. Serve with the sauces on the side, or pile them up and pour both the custard and the cream over the top, allowing them to marble together as they hit the cake.