Butter the inside of a 1 1/2 quart ovenproof dish, set aside.
Liberally butter one side of each bread slice. Then spread 1 1/2 teaspoons ginger jam on each slice, on top of butter.
Build a nine slice sandwich, each slice on top of the other. This step is actually a placement test for pre architectural students, good luck.
Slice all slices/tower diagonally, from corner to corner. Repeat cut from the other corners. You should end up with for triangular towers of slices. If the stand on their own you might want to consider changing careers, unless, of course, you are already an architect.
Place towers in prepared dish, sideways (longwise) with the tips pointing upward. You may vary the rows with the tips pointing in an alternate position, it's more a decorative thing.
Combine the raisins and rum in a microwave safe bowl, you may use water in place of rum, if desired. Microwave for one minute, set aside to cool.
Whisk together eggs, egg yolk, heavy cream, milk and sugar. Pour evenly over the arranged bread slice. Take a break for ten minutes, you won't have time to go shopping so do something fun that lasts only the short ten minute interval. if you've read this entire paragraph, you only have eight more minutes, hurry.
After the ten minute wait, sprinkle raisins evenly over the top. Combine the ground ginger with the granulated brown sugar and sprinkle evenly over the raisins.
Bake in the center of the oven for about 45 minutes but check it after about 40 minutes to avoid burning. I know that charcoal is suppose to be good for you... But not me. So don't burn it, instead bake until nicely browned.