Perform 2 to 3 consecutive refreshes of your pasta madre at a 1:1:0.45 ratio (e.g., 50g starter + 50g flour + 22.5g water).
Ferment each refresh at 28°C (82°F) until it reliably triples in volume before starting the first dough.
Add water and sugar to the mixer bowl and mix briefly to dissolve. Tear active pasta madre into small pieces and add to the bowl along with the flour.
Mix for 7–8 minutes until gluten begins to build and wraps around the hook.
Gradually add softened butter in portions (4–6 minutes of kneading) until fully absorbed and smooth.
Add egg yolks in 2–3 additions, allowing each to incorporate before adding the next. Knead until smooth, elastic, and pulling cleanly away from the bowl.
Transfer to a straight-sided container, mark the level, and ferment at 22–24°C (72–75°F) for 12–16 hours until tripled in volume (target pH 5.1–5.2).
Place all of the tripled first dough into the mixer. Add 30 g flour, diastatic malt, sugar, water, honey, and first 30 g portion of pumpkin purée. Mix on low speed (~25–30% speed) for ~15 minutes until smooth and strong.
Increase speed to ~45%, add softened butter in two additions, then add vanilla, pumpkin spice, and salt. Knead 4–5 minutes until incorporated.
Add egg yolks in two additions (at ~60% speed), mixing thoroughly for about 5 minutes between additions.
Mix in the remaining 30 g pumpkin purée until fully incorporated and the dough passes a delicate windowpane test.
Gently fold in the 200 g chocolate inclusions on low speed just until distributed.
Rest dough on the work surface for 30 minutes. Divide into two equal portions (~520 g each) and shape into tight, smooth balls (pirlatura).
Place into two paper panettone molds. Proof at 30°C (86°F) for 4–5 hours until the dough rises near the top of the mold and feels airy.
Preheat oven to 290°F (143°C). Bake for 27 minutes.
Increase temperature to 320°F (160°C) and bake for an additional 20 minutes.
Remove from oven, immediately insert panettone skewers through the bottom of each mold, and hang upside down to cool completely for at least 8–12 hours before slicing.