Place first 17 ingredients in a large mixing bowl and stir together
Whisk together the eggs, Guinness and 2 tbsp of the Port and the pour into the other ingredients already in the mixing bowl. Stir until well combined
Cover bowl with a tea towel and place in the fridge overnight for flavours to develop
Next day, grease a 2L Pudding bowl with butter. On baking paper, trace around the bottom of the bowl and around the top of the bowl. Cut out these 2 circles. Use the smaller circle to line the bottom of the pudding bowl.
Pour the pudding mixture into the pudding bowl. Cover with the larger circle of baking paper and press down gently so it it sitting on the pudding mixture
If your pudding bowl has a lid, place the lid on. If not, cover the pudding bowl with a couple of layers of foil. Secure the foil by tying some kitchen string around the top of the bowl
Place an egg ring or something similar in the bottom of the slow cooker to hold the pudding bowl off the bottom of the slow cooker.
Place the pudding bowl on top of the egg ring and pour hot water into the slow cooker so that it comes about ⅔ of the way up the sides of the pudding bowl.
Put the lid on your slow cooker, turn to low/medium and allow to slowly simmer for 7 ½ hours. You will need to top up the water from time to time to keep it at the right level. Always top up with boiling water so as not to decrease the temperature of the water.
Once cooked, turn off slow cooker and allow the water in the slow cooker to cool for ½ hour. Remove the pudding bowl from the slow cooker.
Store the pudding in a cool dark place until ready to serve. May be stored for a few months. When ready to serve, again place in the slow cooker and simmer for 2 hours. Serve with Brandy Butter Hard Sauce, brandy custard, cream or ice cream.