Prepare the apple mix-in. Toss the diced apples with sugar, cinnamon, nutmeg, allspice, and ground cloves in a small bowl. Cover and refrigerate while you prepare the dough. I like to get this step out of the way, but if you want, you can do this right before adding the apples.
Mix and autolyze. Combine the sourdough starter, bread flour, apple cider, and sugar in a large mixing bowl. Stir with a spoon or spatula until you form a sticky dough. Cover with plastic wrap or a damp tea towel and let it rest for 30-60 minutes. This autolyze period allows the flour to hydrate and develop gluten.
Knead in the salt. After the dough has rested, add the salt and gently knead it into the dough, either on the counter or in the bowl. Place the dough in a clean, lightly greased bowl, cover, and let it rest in a warm place (around 80-90°F) for 1 hour.
Stretch and fold. After 1 hour, stretch and fold the dough. To do this, gently pull one side of the dough up and fold it over itself. Repeat on all four sides of the dough. Cover and let the dough rest for another hour. Repeat the stretch-and-fold process two more times, with 1-hour rests in between.
Incorporate the apples. After the final stretch and fold, gently fold the spiced diced apples into the dough. Try to distribute the apple pieces evenly without overworking the dough. Cover and let it rest for one more hour.
Cold proof. Transfer the dough to a well-floured banneton or a bowl lined with a floured tea towel (rice flour prevents sticking). Cover tightly with plastic wrap and refrigerate for 12-18 hours.
Preheat and prepare. In the morning, preheat your oven to 425°F (220°C). If you plan to use a hot Dutch oven method, place your Dutch oven inside the oven to heat. Cut a piece of parchment paper and sprinkle it with cornmeal.
Shape and slash. Take the dough out of the fridge and carefully transfer it onto the parchment paper, seam side down. Dust the top of the loaf lightly with flour. Using a sharp knife or a lame, slash the top in a pattern resembling an apple: a wide oval in the center with curved lines extending outward like the skin of an apple. Add a small “stem” cut at the top.
Bake. Transfer the parchment with the loaf into the Dutch oven. Cover with the lid and bake for 30 minutes. Then, remove the lid and continue baking for 20 more minutes until the crust is golden brown and crispy.
Cool. Carefully remove the bread from the Dutch oven and let it cool on a wire rack for at least 3 hours before slicing. This will help the flavors fully develop and the crumb to set.