A joyful Funfetti sourdough loaf — an artisan sourdough with sprinkles folded in for a cake-like, colorful crumb. Uses an active starter and a short warm ferment followed by a long cold proof to develop flavor and keep crumb structure while preserving the sprinkles' color.
Mix the flour and most of the water with your active starter until no dry flour remains; use most of the water now and reserve a small amount to add later if needed. The dough will be slightly tacky but manageable.
Let the dough rest for a short autolyse (about 20–30 minutes) to hydrate the flour. After resting, sprinkle the salt over the dough and incorporate it by pinching and folding; add the reserved water if the dough feels too stiff.
Perform a series of gentle stretch-and-folds every 20–30 minutes for about 2 hours while keeping the dough warm, until it has gained some strength and elasticity. Aim for a total warm bulk fermentation time of around 4.5 hours at a warm room (about 26–28°C).
Lightly flatten the dough on a clean surface and sprinkle the sprinkles over the dough. Gently fold the dough over them and perform a few turns to distribute the sprinkles without overworking; try to avoid prolonged mixing so the colors don’t bleed excessively.
Shape the dough into a tight round or oval and place it seam-side up in a floured proofing basket or a bowl lined with a floured towel. Cover and transfer to the refrigerator for a cold proof overnight — about 18 hours — to develop flavor.
Preheat your oven with a Dutch oven inside to high heat. Bake the loaf covered at a very hot temperature until the crust sets, then remove the cover and lower the temperature to finish baking until golden and well colored. A good schedule is to bake covered at about 260°C (500°F) for around 15 minutes, then uncover, reduce heat to about 230°C (450°F) and bake for another 20 minutes. Adjust times for your oven and vessel size.
Cool the loaf completely on a rack before slicing — this helps set the crumb and keep the sprinkles from smearing further. Once cooled, slice and enjoy the playful, colorful crumb.