Make the levain: In a medium glass jar or mixing bowl, combine ripe sourdough starter, granulated sugar, all purpose flour, and water. Mix well. Lightly cover and leave to ferment at room temperature for 12 hours.

After 12 hours, check the levain for ripeness. It should be bubbly and risen with a mild sour aroma. If not ready, check again in 30 minutes. If ready, begin preparing the dough.

Prep the butter: Remove from the fridge and cut into 1/2 inch pats. Allow to warm to cool room temp, microwaving for a few seconds if needed.

In the bowl of a stand mixer, add the milk, sugar, salt, cardamom, eggs, flour, and entire ripe levain. Fit the stand mixer with the dough hook and mix on low speed until thoroughly combined. The dough will be sticky.

Keep the mixer running on low speed and add the butter 1-2 pats at a time, allowing to become completely incorporated between additions.

Once all the butter is added, increase mixer speed to medium, and mix until dough starts to pull from sides of bowl and ball around the dough hook (it will remain a little sticky), about 5 minutes.

Scrape the dough from the edges of the bowl. Place in a container for bulk fermentation. Cover lightly and leave to ferment on the counter.

After thirty minutes, perform a set of stretch and folds on the dough. Repeat twice more at 30 minute intervals. Cover and leave to sit at warm room temperature for remaining bulk fermentation time, 2 hrs 30 minutes, for a total bulk fermentation time of 4 hours.

At the end of four hours, assess for signs of readiness. This dough does not dramatically rise, but a few bubbles should be present, the top should be much smoother, the sides should have a slight "dome" shape sloping down to the bowl. If these signs are not present leave to ferment 30 more minutes and check again.

Lightly flour a work surface and scrape dough out onto the surface. This recipe can make one large braided loaf or two medium ones. If making one loaf, divide dough into three pieces. If making two loaves, divide dough in half, then each half into thirds.

Roll each piece of dough out into a long cylinder. Stick three pieces of dough together on one end and braid strands together. Join ends together. Turn each end under slightly. Line a baking sheet with parchment paper and transfer dough to prepared baking sheet. Repeat if making two loaves.

Lightly cover loaves and place in the fridge for cold proof, 12-24 hours.

Remove baking sheet from fridge and place on counter at warm room temp for warm proof. Allow to sit for two hours. Again, dough will not rise dramatically, but it will become very soft.

Toward the end of proof time, preheat oven to 400 degrees Farenheit.

If desired, beat egg with 1 Tbsp milk or cream, and use a pastry brush to brush over loaf. Top with pearl sugar and/or sliced almonds or leave un-topped.

Bake for 25-30 minutes if baking two loaves, 27-35 minutes if baking one large loaf. Remove from oven when golden brown and fragrant.

Allow to at least partially cool before slicing. Enjoy at room temp or slightly warmed, with a cup of good coffee!