1. In a large bowl, add the yeast to the warm milk. Let stand for 5 minutes to let the yeast proof - it should expand and proof after just a few minutes. This will ensure your yeast is active.
2. Once yeast has proofed, add the melted butter, sugar, egg, salt, and 1 cup of the flour. Stir everything together until you have a thick paste.
3. Continue adding the flour, 1/2 cup at a time, until the dough begins to pull away from the sides and you're able to knead it with your hands. You may not need to use the full 3 cups of flour; only use enough to create a malleable dough.
4. Turn the dough onto a lightly floured surface and knead in the raisins and nuts. Knead for about 6-8 minutes, or until the dough is smooth and supple.
5. Lightly oil a large bowl. Place dough in the bowl, cover, and let rise for about 1 1/2 hours or until doubled in size.
6. Once the dough has risen, punch it down and knead it into a large rectangle.
7. Roll marzipan into a log that will fit inside the dough.
8. Place the marzipan at one end of the dough, then roll up the dough and pinch the seams together to seal.
9. Place the stolen loaf in a greased loaf pan, cover, and let rise for 45 minutes or until doubled in size.
10. Preheat oven to 375°F (190°C). Bake loaf for 10 minutes at 375°F, then reduce heat to 350°F (180°C) and bake for another 30 - 40 minutes, or until golden brown. When the loaf is done, it should sound hollow when you knock on the bottom of it.
11. Let cool and dust with icing sugar before serving. Stollen will keep for about 3 days if stored at room temperature in a sealed bag.