Levain (Prepare ~4 hours before mixing) -mix all ingredients together until fully combined. Allow to ferment at room temperature for ~4 hours.
Cocoa Paste - Slowly whisk the cocoa powder and optional cinnamon into the liquid to make a smooth paste.
Inclusion Prep - Roast hazelnuts at 350°F (175°C) until golden and fragrant (approx 15 min). Cool and lightly crush.
Method for final dough - mix flours and Water 1 (502g) until just combined. Cover and let rest for 1 hour.
Add the Levain (139g) and mix for 4–5 minutes. Add the Salt (15g) and mix for another 4–5 minutes. Gradually incorporate Water 2 (126g) in 3–4 additions, mixing between each. Add the Cocoa Paste and continue mixing until fully blended.
Gently fold in the roasted hazelnuts, dried cherries, and milk chocolate until evenly distributed, avoiding overmixing.
Target final dough temperature: 78–81°F (26.5-27.5°C).
Bulk ferment for 3 hours, performing 2 folds during bulk (first at 45 minutes, second at 90 minutes).
Divide into two 875g portions. Light pre-shape, rest for 20–25 minutes.
Shape as boules or batards.
Cold proof overnight in the fridge for 12–18 hours.
Preheat oven to 450–485°F (232–252°C). Bake with steam for 20 minutes. Vent the oven and bake uncovered for an additional 20 minutes until fully set and golden.
