In a large bowl, mix together the starter and water.
Add the flour and salt. Mix until a shaggy dough forms. Let that rest for 1 hour covered with a clean, damp towel.
After one hour, perform one set of stretch and folds. Take one side of the bread with wet hands, lift the dough and stretch it over to the other side of the dough. Do that 3 more times while turning the bowl so all sides of the dough have been stretched. Let that sit at room temperature, covered, for 8-10 hours or until it has doubled in size (or overnight).
In the morning, peel the apples and cut them into very small pieces. Place the apples into a small saucepan over medium heat. Add the cinnamon and butter. Cook until the apples are softened. Remove from the heat and let it cool to room temperature.
In the morning, turn the dough onto a lightly floured surface. Spread the dough evenly over the floured surface. Take the apple mixture and spread it over the dough.
Time to shape the dough. Taking one side at a time, turn the dough into the center of the dough. Continue shaping it until a boule shape forms (see pictures in blog post). Flour a large bowl and place the dough into the bowl seem side up. Place it in the refrigerator for at least 1 hour, but up to overnight.
Preheat the oven to 450 degrees. Turn the dough onto a piece of parchment paper. Slash the top of the dough with a lame or a sharp knife. Place the dough into the preheated Dutch oven. Bake for 30 minutes covered, and then 30 minutes uncovered.
Remove the bread from the oven and let it cool to room temperature before cutting.