1. 1. Activate the Starter and Yeast: In a large mixing bowl, combine the active sourdough starter, warm water, active dry yeast, granulated sugar, and salt. Stir gently until everything is well combined and the yeast starts to bloom (you’ll see a slight foam on the surface, indicating it’s active).

2. 2. Mix the Dough: Gradually add the all-purpose flour to the wet ingredients, mixing with a wooden spoon or a stand mixer with a dough hook until a shaggy dough forms. Once the flour is mostly incorporated, add the finely diced apples and ground cinnamon. Continue mixing until the dough comes together and the apples and cinnamon are evenly distributed.

3. 3. First Rise (Bulk Fermentation): Cover the bowl with plastic wrap or a damp kitchen towel. Let the dough rise in a warm place for 3-4 hours, or until it has noticeably increased in size and looks bubbly. For a more complex flavor, you can place it in the refrigerator overnight for a slow, cold fermentation.

4. 4. Shape the Loaf: Gently turn the dough out onto a lightly floured surface. Avoid overworking it. Gently shape it into a round or oblong loaf. If using a proofing basket (banneton), lightly flour it and place the dough seam-side up. If not, place it directly on a parchment-lined baking sheet.

5. 5. Second Rise (Proofing): Cover the shaped dough loosely with plastic wrap or a damp towel and let it proof at room temperature for 1-2 hours, or until it looks puffy and springs back slowly when gently poked.

6. 6. Preheat and Prepare for Baking: About 30 minutes before baking, preheat your oven to 400 F (200 C). If using a Dutch oven, place it in the oven to preheat as well. If baking on a baking sheet, ensure it’s lined with parchment paper.

7. 7. Bake the Bread: If using a Dutch oven, carefully transfer the dough into the hot Dutch oven, score the top with a sharp knife or razor blade (a simple “X” or a few parallel lines work well), cover, and bake for 30 minutes. Then, remove the lid and bake for another 10-15 minutes, or until the crust is golden brown and the internal temperature reaches 200-210 F (93-99 C). If baking on a baking sheet, score the dough, brush with melted butter, sprinkle with turbinado sugar (if using), and bake for 35-40 minutes, or until golden brown.

8. 8. Cool Completely: Once baked, transfer the bread to a wire rack to cool completely before slicing. This is crucial for the texture to set properly.