1. Combine the starter ingredients together to form a dough (knead with a spoon or your hands if needed) and let the starter rise for about 4h to 5h (it can take more or less time, depending on your starter and room temperature). It will be ready when it has risen to its peak (generally they rise by 50%) and it has just started to deflate.
2. Add the flour blend amount for the first dough to the bowl of a stand mixer (or to a large bowl if using a handheld mixer with hooks). Add the water, the starter, and one of the eggs and start mixing at low speed until it forms a dough.
3. When combined, add the second egg. Raise the speed to medium. The dough should be fairly hydrated, thicker than a batter but definitely looser than a bread dough. Add the sugar until combined, in two batches. Finally, add the butter until combined, in two batches. Keep mixing until you reach 15 minutes total mixing time (it is indicative, there is no gluten so the main objective is to have all ingredients combined extremely well but also to work the proteins – it generally takes about 7-8 minutes to work in ingredients, then I keep mixing for 7 min more).
4. When done, cover the bowl very well (for example, with plastic wrap) and let rest at room temperature for 1 hour, or until the dough is fully risen (it will almost double in volume).
5. At least 30 minutes before mixing the rest of the ingredients, prep your raisins/pistachio/chocolate as following. If using raisins and candied fruit, cover them with filtered water so that they will hydrate. If using pistachio/chocolate chips, sprinkle them with a little rice flour and put them in the freezer until you need them. I also like to mix the aromatics (vanilla, lemon and orange zest) with the butter, so that it starts infusing.
6. Start to again mix the dough that just finished fermenting at low speed. Add the remaining flour that was set aside and water (50g) and mix until combined. Raise the speed to medium and add the yolks. Mix until incorporated. Add the sugar, in two batches. When incorporated, add the butter and the aromatics (vanilla paste, lemon and orange zest), in two batches. Finally add the salt. Mix until you reach 15 minutes total mixing time (again, indicative time).
7. Drain the raisins and candied fruit or take the pistachio/chocolate chips from the freezer and remove excess flour (depending if using raisins or pistachio/chocolate). Lower the speed of the mixer to minimum and add the raisins or pistachio/chocolate. Mix for a very short amount of time, until incorporated. Remove the bowl from the stand mixer and with the help of a spatula fold the dough onto itself to make sure raisins/ pistachio/chocolate are well distributed in the mass of the dough. The dough should be very soft and thinner than a bread dough. You should be able to almost pour it, but you will need the help of a spatula to push it off the bowl.
8. Put your Panettone mould on a small baking tray you can easily move around. Pour the dough into the mould, with the help of a spatula. It should fill the mould up to 60-70% of its height (so a bit more than half). Gently grab the mould by its edges, lift it a few centimetres, and drop on the table/baking tray to push out air and make the dough levelled.
9. Cover with an upside-down pot or large bowl so that the mould is covered but the dough will not stick to the cover or touch it at any time (again, it is very delicate). Let rise for 2 to 3 hours, or until the dough has almost reached the hedges of the mould and shows a slight dome-like shape on top.
10. To make a glaze, add the nuts to a food processor and blitz until powdered (but do not take it too far, or they will become nut butter). Add the starch first and combine. Finally add the rest of the ingredients and blitz for a minute or two until well combined and slightly thickened. If too thick, thin it out with more egg white or water. Keep in mind that the dough will be extremely delicate: there is no chance to spread the glaze with a spoon or brush, so it should be thickened but still runny so that it will coat the panettone without spreading it.
11. 1 hour before the second rise is over, pre-heat your over at 170C° (160C° fan). When the second rise is over, if using gently drop a few teaspoons of glaze on top of the panettone dome, letting it run naturally over it (do not spread it). Move the tray with the panettone on a rack in the middle of the oven and bake for 1 hour or until the internal temperature reaches 95C° (due to the high hydration, sometimes it can get past it and reach close to 100C°, that is fine).
12. When ready, gently pierce the panettone a couple of centimetres from the base with two skewers. The skewers should be parallel between themselves and far apart. They should pierce the panettone from one side and come out from the other. This process should be done quickly, so the panettone can be hanged upside-down asap.
13. Once the skewers are in place, gently flip the panettone and hang it upside-down on a pot to cool (the panettone will not touch the bottom of the pot because it will be suspended by the skewers laying on the edges of the pot).
14. Let the panettone cool down until cold (at least 2H), but ideally more than 4H or overnight.

If using, sprinkle some pearl sugar on the panettone. Slice and serve with coffee or with some good quality nut cream, pistachio cream or almond cream work great as well.