Overnight Fluffy Sourdough Milk Bread Rolls

Directions

1. Build Levain (12pm): Combine 60g sourdough starter, 90g bread flour, 90g water, and 35g sugar in a jar. Leave it in a warm place to rise until doubled (~6-8hrs at 22C).
2. Make Yudane (12pm): Carefully combine 90g boiling water and 90g bread flour in a heat-safe bowl and whisk until all the flour is hydrated and the mixture forms a thick paste. Cover and let cool for a few hours until it's time to build the final dough.
3. Final Dough - Autolyse (6pm): Mix together all final dough ingredients except for salt and butter until all the flour is hydrated. Cover and leave for 30 minutes. Note: You'll only use 255g of your levain - keep the remaining amount as your starter.
4. Final Dough - Mix Pt. 1 (6:30pm): Add salt to the dough and knead until the dough feels smooth and elastic, about 5 minutes by hand or 3 minutes on low in a stand mixer.
5. Final Dough - Mix Pt. 2 (6:40pm): Add butter to the dough one cube at a time, mixing in between and ensuring the butter is fully incorporated before adding more. Continue to knead until the dough reaches the windowpane stage (can take ~10-15min in a stand mixer on low), meaning you can stretch the dough thin enough to see light come through without ripping. The dough should be smooth, shiny, and stretchy.
6. Final Dough - Bulk Ferment (7pm): Transfer to a clean and lightly oiled bowl, cover, and let rise at room temp (for me, ~22C) for 2.5 hours. The dough should have expanded somewhat but not doubled.
7. Final Dough - Shape (9:30pm): Transfer dough onto a lightly floured surface and divide into twelve 82g pieces. Shape each piece into a ball: take each edge and fold into the centre, flip over, then use your hands to round into a tight boule by turning and lightly dragging across the surface. Place the shaped rolls into a lightly greased 9-inch round baking pan (a springform works great) and cover with plastic wrap.
8. Final Dough - Overnight Proof (10pm): Leave the dough to proof overnight at room temperature, around 10 hours (at ~22C). Depending on how cool your kitchen is, this may take a little longer. To speed up the proof, you can place the pan in the oven (turned off!) with the light on.
9. Final Dough - Bake (8am, Next Day): Pre-heat your oven to 180C/350F (160C/325F convection). Check that the dough has proofed — the rolls should be noticeably puffy and if you lightly poke one, the indentation should spring back slowly. When ready to bake, lightly brush the rolls with 1 tbsp milk and transfer to oven. Bake for 35min or until internal temp is >96C/195F. Check the rolls 20min into the bake; if it's browning too quickly, place a piece of foil over the top for the rest of the bake.
10. Final Dough - Enjoy: Remove from oven & brush a little extra melted butter onto the top if desired. Immediately turn the rolls onto a cooling rack. Let cool completely and enjoy!