To make the Marzipan (optional in the recipe):
In a bowl pour the icing sugar and almond powder, mix well.
Add water, Rum, and almond extract. Knead by hand to form a ball (like a pastry).
Make a roll with the dough and put in the refrigerator in a plastic wrap until ready for use.
To make the Stollen:
In a bowl, macerate the raisins in the Rum (or Kirsch) and water.
Sift 100g flour in a bowl, add yeast, 1 tbsp of the 70g sugar and warm milk, mix well. This is your "sourdough starter". Cover with plastic wrap and let sit 15 minutes at room temperature.
During this time, incorporate the rest of sugar into the butter, add the salt, eggs, lemon zest and mixed well until it is creamy.
In a stand mixer, put the rest of flour (400 g), add "sourdough starter" and the mixed of butter. Mix at slow speed until well combined.
Add the soaked raisins, almonds, candied oranges and candied lemons. Still beat for a few moments, then roll the dough into a ball. Place it in a large bowl and cover with plastic wrap or a towel and let it rise one hour at room temperature.
Roll out the dough in a thick shape of rectangle.
Take the Marzipan, rolling it gently until you have the same length of the Stollen. If it is too sticky, put a little bit of powdered sugar. Place the Marzipan along the dough's length and fold the top half of the dough over the bottom half, leaving a one-inch strip of the bottom edge exposed.
Let it rest for 30 min.
Preheat the oven to 390F then lower to 355F when you put the Stollen inside.
Cook for about 40-45 min.
Once cooked, place the Stollen on a grid. Melt a few tablespoons of butter and brush well the entire Stollen while it isstill hot with the melted butter. Copiously sprinkle the icing sugar and let it cool completely.