This is an adaptation of Chef John's recipe to make it easier for a not-very-good cook such as myself (which is not to say the original recipe isn't easy).
When juicing the orange, it's much easier if you cut it into quarters. Squeezing through a sieve or strainer will prevent orange seeds from getting into your batter.
Here in the US, you can buy most of these ingredients pretty easily. For the various dried fruits, try to get those that are just fruit without added sugar. This is almost impossible for cranberries, though, so just try to find ones that don't have a lot of added sugar.
Again, here in the US, crystallized ginger can often be found in the spice section of the grocery store in little spice bottles. In my experience, you'll need about one whole of the little bottles for this recipe.
There's no sugar in this cake, except that provided by the dried fruit. It's not super sweet, but there is a sweetness to it. If you need it sweeter, putting some maple syrup on afterwards is pretty good, but I like it as is.
Butter the inside of a heat proof, oven-safe glass bowl.
Combine the fruit, orange juice, ginger, and bourbon in the bowl. Stir well.
Pour in melted butter and stir well until everything is coated. Mix in egg, cream, and buttermilk. Add remaining ingredients and stir until batter is very thick, being sure to mix well so that the various ingredients are evenly distributed.
Pack the batter into the bowl, and smooth down the top. Cut a circle of baking parchment paper slightly larger than the diameter of the bowl and press down on top of the batter, being sure to seal it over completely.
Refrigerate overnight. When removing the bowl the next day, double check that the parchment paper is still tightly pressed down over the batter. Cover the bowl with two layers of aluminum foil and then tightly tie the foil with butcher's twine.
Lay kebab skewers in the bottom of the Dutch oven and place the bowel with the batter on top. Fill the Dutch oven with water up to halfway up the side of the bowl.
Cover and turn the heat on high. When the water boils reduce the heat to medium. Keep the cover on the Dutch oven.
Simmer on medium heat for 4 hours. At the 45 minute mark of every hour, put the full teakettle on to boil. At the hour mark, check if the water has gotten too low in the Dutch oven; if so, refill with boiling water from the kettle. Don't forget to turn the kettle off and refill it as well, as needed. :) This little dance is necessary so that you don't boil off all the water in the Dutch oven, and so that you don't reduce the temperature of the water when refilling it.
After four hours of steaming, carefully (using oven mitts) remove the bowl from the Dutch oven. Remove the foil and parchment paper. Invert the bowl onto a plate to dump out the cake.
It's good hot or cold, and keeps well for a few days when covered.