Impastare (Yeast mixing): In the bowl of a stand mixer, whisk together ⅔ cup (160 g) lukewarm water with the yeast until dissolved. Add 2 cups (150 g) flour.
Using the paddle attachment, beat at low speed until a stiff dough forms. NOTE: If the flour is not fully incorporated, knead dough in a bowl by hand until fully combined.
Cover and let the dough rise in a warm, draft-free place (75° F/ 24° C) until doubled in size (about 15-20 minutes). NOTE: If you are in a cold place, place the bowl, covered, inside of the oven or microwave.
Then add 4 cups (500 g) flour, granulated sugar, and salt to the yeast mixture. Add 4 eggs (200 g), lukewarm milk, vanilla, and orange zest. Beat everything at low speed until a shaggy dough forms, making sure to scrape the sides of the bowl.
Switch to the dough hook attachment. Beat the dough at low speed until it is tacky, soft, smooth, and elastic (about 6 to 8 minutes). Add up to the remaining ½ cup (62 g) flour, 2 tablespoons (28 g) at a time, beating after each addition until combined (3-4 minutes total).
Add the butter, 2 tablespoon at a time, beating after each addition until combined after each addition (3-4 minutes). Make sure to beat until a soft, smooth, and elastic dough forms (5-7 minutes). Turn out dough onto a lightly floured surface, and shape it into a smooth round.
Fermentazione (Fermentation): Lightly oil a large bowl and place the dough inside, turning to grease top. Cover and refrigerate overnight. Then remove the bowl from the fridge and let the dough rest at room temp for about 30 minutes for easy folding.
Piegare (Folding): On a well-floured surface, divide the dough in half. Roll each ball of dough into a ½-inch-thick oval (about 12 x 10 inches).
Sprinkle one of the doughs with half of the drained candied fruits and raisin mixture. Use the palm of your hand instead of the rolling pin to gently press the fruit into the dough. Fold dough in half lengthwise. NOTE: Make sure to wipe off any excess liquid from the fruit. Roll dough into a ½-inch-thick oval. Sprinkle with the remaining fruit mixture. Press fruit into dough, then fold the dough in half crosswise. Re-roll into a ½-inch-thick oval.
Pirlatura (Dough rounding): Fold the dough, shape it into a ball, and place the seam side down, in a 5.9-inch-wide x 3.9-inch-high panettone paper mold (or one with similar measurements). Place the panettone mold on a double rimmed baking sheet. NOTE: If you use only one baking sheet instead of two, there is more probability of the bottom of the paper mold burning a little.
Do the same with the other dough but use the chocolate chips instead. TIP: Make sure to place the 2 paper molds apart from each other (opposite side of the baking sheet to have room to rise).
Cover and let rise in a warm, draft-free place (75° F/ 24°C) until doubled in size, about 1 to 2 hours, or until it reaches the rim of the paper mold.
Position the oven wire rack in the bottom third of the oven. Preheat the oven to 375° F (190° C).
In a small bowl, lightly whisk the remaining 2 eggs (100 g). Brush the top of the 2 bread loaves with egg; sprinkle with pearl sugar.
Scarpatura (Scoring): Using a sharp paring knife, score the top of each loaf with an “X” and place a pat of butter onto the “X”.
Bake for about 12 to 15 minutes or until it is just starting to brown. Then reduce the oven temperature to 350° F (180° C) and bake for 40-50 minutes or until deep golden brown (and an instant-read thermometer inserted in the center registers 190° F or 88° C). Make sure to cover each loaf with aluminum foil after 10 minutes of baking to prevent excess browning.
As soon as you remove the 2 panettones from the oven, insert 2 or more (as many as needed to hold the base) long wood skewer through the base of each panettone (going from one side through to the other) and hang each panettone upside down. Let them cool completely.
NOTE: You can use the clean bowl of your stand mixer as the base to hang the panettone. Some people use the back of two chairs placed just a little apart as the base to hang the ends of the skewer. IMPORTANT: They have to cool upside down; otherwise their tops will deflate and the dough (interior) will be mushy and heavy. Do NOT let the top of the panettone hang upside down touching a surface; otherwise, it will deflate.
Once they cool, remove the skewers carefully and enjoy a slice.