1. Begin by lightly greasing a 1.7 ltr pudding basin with butter. Set aside. Fill and boil your kettle.
2. Roughly chop 150g dark chocolate into chunks. Set aside. Measure 175g plain flour and 30g cocoa powder into a mixing bowl. Add the baking powder and bicarbonate of soda and set to one side.
3. Spoon 150g of the MarmalAID into a separate bowl and mix with the orange liqueur (or orange juice) to loosen. Finely grate in the zest of the orange. Stir to mix, then set to one side.
4. Measure 175g butter and 175g caster sugar into another mixing bowl. Using a stand or a electric mixer, beat the butter and sugar together till pale and creamy. In a small jug or bowl beat the eggs with the soured cream, then very slowly trickle the egg mixture into the butter and sugar, beating welll between each addition till smoothly combined.
5. Sift half the flour and cocoa mix into the butter and sugar, then use a spatula or spoon to just mix them in. Add the MarmalAID mix and stir once or twice to combine. Sift in the remaining flour and cocoa mix and add the chocolate chunks. Fold gently with a spatula or spoon till the mix is smooth and just combined.
6. Pour the pudding mix into the prepared pudding basin. Pop the lid on and wrap the whole basin tightly in 2-3 layers of foil to prevent any water getting inside. If your pudding basin doesn't have a lid, use baking paper to cover the basin instead. Cut a large circle out of a sheet of baking paper, roughly twice the size of the basin, then fold it a 3 in pleat in the middle of the circle. Place the paper over the top of the basin. Top with a large foil circle, also with a pleat in the middle, and tie the paper and foil onto the basin with kitchen string.
7. Carefully lower the pudding basin into a large pan. Pour hot water form the kettle into the pan, around the basin, till it comes to just over halfway up the basin. Fill and boil the kettle again if you need to. Pop a lid on the pan. Simmer gently for 1½ hrs. Check the pan regularly to keep an eye on the water level and top up with more hot water if necessary.
8. When the pudding has cooked for 2 hr 15 mins, make the chocolate sauce. Roughly chop the dark and milk chocolate and add to a medium pan along with the double cream, agave syrup and orange liqueur (or orange juice). Place on a low heat and gently warm, stirring regularly till the chocolate has nearly melted. Remove the pan from the heat and whisk the sauce till smooth.
9. Carefully lift the pudding out of the pan using oven gloves to protect your hands. Unwrap the pudding and remove the lid. Place a large serving plate, upside down, on top of the basin then confidently flip the plate and pudding basin over. Gently wiggle the basin to release the pudding onto the plate.
10. Spoon some of the chocolate sauce over the pudding and pour the rest into a jug. Serve the Chocolate & MarmalAID Pudding with the chocolate sauce and crème fraîche.
11. GET AHEAD
You can start to prepare the chocolate pudding mix the day before you wnat to cook it. Follow steps 1-4, stopping before you add the flour to the buttar and sugar mix. When you're ready to cook the pudding, follow steps 5 onwards then steam straight away. You can make the chocolate sauce up to 3 days in advance and store in the fridge. Reheat gently in a pan or the microwave, stirring regularly.