Stir the yeast and 2 tablespoons (25g) of the sugar into the lukewarm milk and let sit in a warm place for 10-15 minutes until very frothy.
Place the flour, 175g sugar, egg, egg yolks, butter, vanilla extract, lemon zest, salt, cardamom, mace and cinnamon in the bowl of a stand mixer fitted with a dough hook.
Add the yeast/milk mixture. Stir the mixture until it comes together.
Knead the dough on medium for 7-8 minutes.
Remove the dough ball, lightly spray the bowl with a little oil, return the dough ball, cover loosely with plastic wrap and place it in a warm place or slightly warmed oven, to rise until nearly doubled in size, at least 1 hour.
Punch down the dough and add the soaked fruit/nut mixture to the dough (it should have absorbed all the rum by now but if there is excess liquid, pour it out before adding the mixture to the dough).
Using the dough hook, knead the fruit/nut mixture into the dough until combined. If the dough is too wet to handle, add a little bit of flour until the dough pulls away from the sides of the bowl.
Turn the dough out onto a floured work surface and cut it in two equal halves.
Press or roll each piece into an oval to about 1” thickness.
Roll each piece of marzipan into a log the length of the oval.
Press the marzipan gently into the middle of the dough.
Fold the left side of the dough over to cover the marzipan, then fold right side over on top of the left side so that the edge of it sits just left of the middle of the stollen. (In other words, don't fold the right side all the way over to the left edge of the stollen.)
Pinch and tuck the top and bottom ends of the stollen to cover the marzipan.
Use the bottom edge of the hand to press down along the length of the stollen towards the right of the center to create a divot and characteristic hump.
Place on a lined baking sheet. Cover loosely with plastic wrap and let rest in a warm place or slightly warmed oven for 40-60 minutes until puffy. At that point, pick off any raisins that are sticking out of the dough (they will burn during baking).
Towards the end of the last rise, preheat the oven to 350°F and bake for 30-40 minutes or until golden with an internal temperature of 190°F.
Let sit for 5 minutes, using toothpick poke holes all over (this will allow the butter to seep in), then generously brush with melted butter while still warm. Immediately sprinkle with a generous amount of powdered sugar, rubbing it into the creases and down the sides. Let it cool completely.
The Stollen can be sliced and eaten immediately or wrapped tightly (wrap in plastic wrap then foil) and left to “ripen” in a cool place for 2 weeks. The liquid from the dried fruits will further penetrate the dough for more flavor and moisture. Stollen can also be frozen for longer storage.