In a stand mixer, pour the water, the starter broken into pieces, and the rest of the yeast. Combine the K beater attachment until is all dissolved.
Replace the K beater with the hook attachment.
Add the flour and knead at 1 speed for 10 minutes with the hook attachment.
Now add the aromatic honey, the salt, all together, and the sugar one tablespoon at a time and mix at 1 speed for 13 minutes. Let absorb well the previous ingredients before adding another one. This is essential for the creation of gluten. You will notice that the sides of the bowl will be clean and if you touch the dough you will not feel the sugar.
Once all the sugar has been absorbed, pour in the dough one egg yolk at a time and mix at 1 speed. Remember to always let the yolk absorb well before adding another one. After 13 minutes the dough has come together and you will see that it clings to the hook.
Combine the butter, by adding 3 cubes at times, mix at 2 speeds. Again, let the previous butter absorb well before adding another one. After 20 minutes turn off the stand mixer, you will see that the dough is wrapped around the dough hook. At this point, the dough must be shiny and elastic, which means that it has developed gluten. You can see this by doing a windowpane test, gently tear off the dough with your fingers and you will be able to see through. If the dough is breaking, knead again for 2 minutes.
Now pour the candied oranges and the sultana raisins and turn on again the stand mixer at minimum speed for 10 seconds or so. If some of the fruits are left in the bowl you can add them back to the dough when performing the first slap and fold method.
On the work surface, pour the dough and make two series of slap and fold. Leave the dough to rest for 30 minutes covered by a cloth. Repeat the slap and fold, cover the dough and let it rest for another 30 minutes.
It's time to shape* the dough, this process is called "pirlatura" in Italian. Place a left hand on the dough and only with your right hand push the dough towards you. Now use your left hand while the right hand will be close to the dough and push the dough upwards. Repeat until you have a spherical shape. At this point*, place the dough very carefully into the panettone case and cover them with some cling film. Let it rise in a warm place at 26/28 °C. An oven with the light on maybe not be enough. I suggest you place a saucepan filled with hot water in the oven as well as the dough, and check the temperature every now and then. Alternatively, turn the oven to 100°C (212°F) for 10 seconds and turn it off immediately. This will warm up slightly the oven, repeat every now and then. The dough will be ready when it reaches 2 cm from the edge of the cases (about ⅚ hours). Timings depend on how constant is the temperature where the dough is resting. Don't rush it, let the dough rise completely.