Prepare the starter either the night before or in the morning; the important thing is that it doubles in size. I preheated the oven to 105°F (40°C) and let it rise for 3 hours.

First Dough:
* Mix the flour with the powdered milk (dry ingredients).
* Cream the butter and add the sugar blend (fats).
* Take the starter and, using a hand whisk or stand mixer, add the dry ingredients in two stages, then the eggs, then the liquids, and finally the fats (add the fats gradually, but in the second stage).
* Let rise for about 3 to 4 hours, until doubled in size.

Second Dough:
* Mix the flour with the powdered milk, vanilla, and xanthan gum (dry ingredients).
* Cream the butter and add the sugar blend (fats).
* Take the first dough and, again using a whisk or stand mixer, add in two stages: the dry ingredients, the eggs, the liquids, and finally the fats (add the fats gradually, but in the second stage). Finish by adding the orange and lemon zest.
* Add candied fruit, raisins, or chocolate chips as desired.
* Pour into a 750-gram panettone mold and let rise for 3 hours.

Baking:
After the second rise, place in a preheated oven at 340°F (170°C) and bake for 50 minutes.

After baking, for safety, invert the panettone using special skewers and let it cool completely.

Using the same method, I made mini panettones, each about 100 grams. I made 8, baked at 340°F (170°C) in a preheated oven for 30 minutes.