Mix the Dough: Combine the sweet starter, browned butter, milk, rum, vanilla, spices, sugar, and egg in a large bowl. Gradually add the flour and salt, mixing until a shaggy dough forms.
Knead: Knead the dough by hand or with a mixer fitted with a dough hook for 8–10 minutes, until smooth and elastic. Dough will be tacky to touch. Allow dough to rest covered for 30 minutes, and perform one set of stretch and folds.
First Rise: Place the dough in a greased bowl, cover, and let rise at room temperature for 8 hours at 78-80 degrees. Dough won't double, but should show signs of puffing and fermenting.
Baker's Schedule (5:00 PM- Day 2)