In a large bowl, whisk the 1 cup starter, 1 1/4 cups warm water, and 1/4 cup molasses until smooth. Add the 3 cups flour, 1 1/2 tsp salt, 2 tsp ginger, 1 tsp cinnamon, 1/4 tsp nutmeg, and 1/4 tsp cloves. Mix until no dry flour remains. Cover and rest 30 minutes.

With a wet hand, do a set of 4 stretch-and-folds. Cover and repeat 3 more sets at 30-minute intervals, about 4 sets over 2 hours.

Turn the dough onto a floured surface. Shape it into a tight boule, then rest 10 minutes. Final shape by dragging the dough to tighten the skin. Place seam-side up in a floured banneton or bowl lined with a floured towel.

Cover and proof at warm room temperature until puffy and a fingertip leaves a slow spring-back, 1 to 2 hours.

Meanwhile, preheat the oven to 450°F (230°C) with a Dutch oven inside. Turn the proofed dough onto parchment, score the top, and carefully lower it into the hot pot. Cover and bake 30 minutes, then uncover and bake 15 to 20 minutes more until deep brown.

Cool on a wire rack for at least 1 hour, then slice and serve.