Dissolve the salt and sugar into the water and stir in the vanilla. Add half of the flour and mix the dough thoroughly using a spoon. Add the ripe sourdough starter and vigorously mix with the spoon for 3 minutes.
Add the rest of the flour, pinching and squeezing it into the dough until it has thoroughly come together. Use the Rabaud method of mixing sourdough for 3 minutes, then cover and rest for 30 minutes.
Mist your work surface with water and turn out the dough. Use a wet hand to knead the dough, using the slap-and-fold method. After 5 minutes of working the dough, use a bench scraper to shape it into a boule. Cover and ferment for 1 hour.
Do a coil fold, then cover and ferment for one more hour.
Mist your working surface and laminate the dough. To do this, gently stretch the dough into a large, thin square. Work your way around the edges, lifting and pulling carefully until the dough is stretched as far as possible without tearing. See the process photos for guidance. Spread half the apple chunks evenly across the dough.Fold the dough like an envelope into thirds, taking the left side of the dough and folding it over to the center, adding more apples, then taking the right side and folding it over the left, adding the remaining apples. Then, roll or fold the bottom of the dough towards the top. Shape the dough into a round boule, tightening it as you pull it towards yourself. Cover and bulk ferment for 5 to 8 hours or until it has increased in volume by 75%. Flour the top of the dough and turn it out onto the counter for preshaping. To do this, slightly flatten it out by pressing with your fingers, then take the right upper edge of the dough and fold it over while grabbing the left upper edge and folding it over in a stitching movement, pinching it together. Repeat this movement for the lower edges. Then, grab the bottom edge and tuck the dough into a ball, rolling it up from the bottom to the top. Rest uncovered for 20 minutes.
Flip the dough over and do another shape, pinching and sealing the seam. Coat the shaped boule in flour and place it seam-side up in a lightly dusted cloth-lined proofing basket. Cover and proof overnight (up to 15 hours) in the refrigerator.
Do a final shape and place the dough on a piece of parchment paper to rest for another 2 hours at room temperature. Place a layer of rice on the bottom of a Dutch oven, fold a square of aluminum foil, and place it on top of the rice. Near the end of the 2 hours, place the Dutch oven inside the oven and get it preheating to 450F (232C). Always use heavy-duty oven mitts when working with a hot Dutch oven!
Score the dough, then lift the parchment paper, with the boule, and place it into the Dutch oven. Bake with the lid on for 40 minutes. Using an oven mitt, remove the Dutch oven lid, and bake uncovered for another 10 minutes.
Allow the bread to cool on a wire rack for 2 hours before using a sharp bread knife to slice and serve.