Soft Rosemary Seeded Spelt Sourdough Batard

Steps

1. The night before (about 9 pm), feed your starter and leave it at about 75°F (24°C); it should peak, doubled and bubbly, in 8 to 12 hours. Use 100 g of it for this loaf.
2. In a dry skillet, toast the sesame seeds and pumpkin seeds over medium heat for 3 to 4 minutes until fragrant, then cool. Set aside a quarter of the sesame seeds and a quarter of the pumpkin seeds for the top; the remaining three quarters go into the dough.
3. In a large bowl, whisk the water, milk, sourdough starter and maple syrup until the starter is loosened.
4. Add the spelt flour and bread flour and mix until no dry patches remain. Cover and rest 30 minutes.
5. Sprinkle the salt over the dough, add the olive oil, and squeeze and fold until fully absorbed. Counting the milk and the starter, this dough is about 73% hydration and 2% salt against the combined spelt flour and bread flour.
6. Add the rosemary, flaxseed and the three-quarter portion of toasted sesame seeds and pumpkin seeds; fold until evenly spread.
7. Bulk rise covered at about 75°F (24°C) for 4 to 5 hours. During the first 2 hours, do 4 sets of gentle stretch-and-folds 30 minutes apart; spelt dough is delicate, so handle it lightly. Bulk is done when the dough has grown about 50% and looks airy and domed.
8. Line a baking sheet with parchment. Turn the dough out, pat it into a rectangle, roll it up snugly into a tapered batard and set it seam-side down on the parchment.
9. Brush the top with half of the melted butter, then press on the reserved quarter of sesame seeds and pumpkin seeds.
10. Cover loosely and cold proof in the fridge overnight, 10 to 14 hours. Next morning, leave it at about 75°F (24°C) for 1 to 2 hours, until puffy and it springs back slowly when poked.
11. Preheat the oven to 400°F (200°C) for 30 minutes, then make one shallow slash along the length of the batard.
12. Bake 35 to 40 minutes, until golden and 200°F (93°C) in the center.
13. Brush the hot crust with the remaining half of the melted butter and tent loosely with a clean towel for 15 minutes to keep the crust soft.
14. Move the loaf to a rack and cool for at least 2 hours before cutting into 12 slices.