Mix the starter, flours, and water until shaggy. Let rest for 30–40 minutes (autolyse).

Add salt and maple syrup. Mix until incorporated and smooth.

Bulk ferment for 4–5 hours at room temperature, folding the dough 3–4 times during the first 2 hours.

Toast the pecans and prepare the filling: stir together the butter, brown sugar, maple syrup, and cinnamon until creamy. Fold in the chopped pecans.

Turn the dough onto a lightly floured surface and gently press into a rectangle.

Spread the filling evenly over the dough, leaving about 1 inch border along one short edge.

Roll the dough tightly into a log, seam-side down.

Trim the ends slightly so the loaf fits neatly into your pan or tin.

Place seam-side down in a lightly greased loaf tin or banneton.

Cover and proof for 2–3 hours at room temperature, or refrigerate overnight (8–10 hours).

Preheat the oven to 450°F (230°C). If baking in a Dutch oven, preheat it as well.

Score the loaf, then bake covered for 20 minutes. Uncover and bake another 25 minutes, until golden brown and fragrant.

While still warm, brush the top with maple syrup and sprinkle with extra chopped pecans if desired.

Cool fully before slicing to reveal the swirl inside.