Step 1

Make the dough: Mix the flours and water together in a large mixing bowl using a stiff spatula or wooden spoon until a shaggy dough forms and no traces of dry flour remain. Cover the bowl with plastic wrap and let the dough rest for 30 minutes to 1 hour.

Step 2

Fold the active sourdough starter and salt into the dough. Knead the ingredients in until you no longer feel any grains of salt. Transfer the dough to a clean, lightly greased container and cover with plastic wrap. Let the dough rest in a warm spot for 30 minutes.

Step 3

Add the mix-ins: Add half of the chopped dates and nuts on top of the dough. Pick up one side of the dough and fold it over the mix-ins. Repeat with the remaining add-ins, cover the dough with plastic wrap, and let the dough rest for 30 minutes.

Step 4

Coil Fold: Perform 3 sets of coil foils in 30 minute intervals. Cover the bowl with plastic wrap and set in a warm place in between sets.To perform a coil fold, working with the dough inside the bowl, lift the center of the dough up with your fingertips until the ends release from the container. Lightly set the dough back down into the bowl and tuck the ends under.

Step 5

First proof: After the last coil fold, let the dough rise untouched until the dough looks well risen and bubbly, about 1 ½ to 2 hours.

Step 6

Pre shape the dough: Place the proofed dough onto a lightly-floured clean counter. Using a bench scraper, turn the dough over and lightly round it into a tight ball. Cover with a clean tea towel and let the dough rest for 30 minutes.

Step 7

Shape the dough: Turn the dough over once more, flatten it out into a rectangle. Fold the side closest to you towards the center and the top of the dough over the bottom flap. Fold the sides over each other. Flip the dough and round it into a boule. Place the dough into a prepared banneton with the seam side up.

Step 8

Cold proof: Cover the banneton with plastic wrap. Transfer the dough to the refrigerator to proof overnight (about 8 to 16 hours).

Step 9

Prep: Preheat the oven to 500 F with a Dutch oven inside.

Step 10

Score the dough: Turn the proofed dough out on a piece of parchment paper. Score the top of the loaf with the pattern or design of your choice, and make sure the cut is at least a ¼-inch deep.

Step 11

Bake: Transfer the dough into the Dutch oven with the parchment paper.

Step 12

Turn the oven temperature down to 450 F, bake for 25-30 minutes covered and 10-15 minutes uncovered.

Step 13

The loaf is baked when it registers at least 190 F when probed with an instant-read thermometer and reaches your desired level of browning.

Step 14

Enjoy: Transfer the baked loaf to a cooling rack and cut the strings off. Let the bread cool for at least 2 hours before slicing.

Step 15

Store: Store any leftover bread for up to 3 days in an airtight container at room temperature.