Prepare the dry ingredients: In a large bowl, whisk the bread flour, cranberries, walnuts, whole wheat flour, oats, flaxseed, yeast, salt, and cinnamon (if using) until well combined. Set aside.

Prepare the wet ingredients: In a large microwave-safe bowl, stir together the water and pumpkin puree and microwave in 30-second intervals until slightly warmer than bath water, approximately 115°F, 1 to 2 minutes. Stir in the honey and olive oil. Add the pumpkin mixture to the dry ingredients and mix with a wooden spoon until just incorporated and the dough is shaggy. Cover the bowl with plastic wrap and a towel and let stand in room temperature until doubled in size, about 3 hours.

Form the dough: Generously flour a surface. Turn out the dough and sprinkle with a little flour. Using floured hands, gently stretch a corner of the dough, stretch it upward, and fold it over to the opposite side of the ball. Grab the next corner, stretch it upward, and fold it over. Repeat with the remaining two corners. Then repeat the full set again, for a total of 8 folds. Flip the dough over and shape into a ball.

Line a large bowl with parchment paper. Place the dough seam-side in the bowl and cover with plastic wrap and a towel. Allow the dough to rest again until fully proofed and you can poke your finger about an inch into the dough without the indentation bouncing back immediately, 1 hour.

About 15 minutes into the second proof, place a 4- to 6-quart Dutch oven or oven-safe pot with a lid in the cold oven on the middle rack. Preheat the oven to 425°F with the pot in the oven for 30 minutes. Fill a small bowl with water and place it next to the oven.

Bake the bread: Remove the pot from the oven and, taking care not to burn yourself, immediately add the parchment paper with the dough into the pot. Brush the dough with a little water, then sprinkle 1 tablespoon of oats over the top. Cover with the lid and bake for 25 minutes.

Remove the lid from the pot and continue baking until the bread is golden and makes a light hollow sound when tapped, 8 to 12 minutes. Carefully grab on to the parchment paper and immediately remove the bread from the pot and transfer to a wire rack. Allow the bread to cool completely, at least 2 hours, before cutting into 12 slices.

To serve: Toast the slices until nice and golden brown on the edges. Spread with optional Salted Honey Butter and a little flaky sea salt. Serve with optional Salted Honey Butter (page 235, optional).

To store: Place bread in a resealable storage bag for up to 2 days, then transfer to the freezer. To freeze the baked bread, allow it to cool to room temperature, then cover the baked bread tightly in plastic wrap, seal in a freezer bag, and freeze for up to 3 months. You can also slice your bread before freezing it, so you can defrost individual slices for toasting as needed.