In a large bowl, add sourdough starter, water, raisins, cinnamon, sugar, whole wheat flour, and bread flour. Mix to form a shaggy dough. Cover and set aside for 30 min.
Sprinkle salt over and pinch to incorporate. Stretch and fold each quarter to create a ball and flip upside down. Let rest for 30 min.
Perform a series of stretches and folds (with a wet hand to prevent sticking) every 30 minutes for 2.5 hours for a total of 5 times. Flipping upside down after each time. You should notice the dough beginning to rise and air pockets forming.
Pour out onto a lightly floured surface and form a tight ball by tucking and twisting the sides.
Flour the surface of the dough and the banneton (or small bowl if using) and place dough upside down inside.
Cover and let rest at room temperature for 1-2 hours if time allows. Then, place in the fridge overnight for the long ferment.
Side note: If your dough is not rising and air pockets are not forming, you may need to let it sit at room temperature for a few hours before baking. Gently press your finger down on the dough. If it springs back, it's ready to bake.
Preheat your oven to 450°F with your empty Dutch oven inside. Place a baking sheet on the rack below. This helps prevent the bottom of your loaf from getting too dark.
Flip dough out onto a lightly floured piece of parchment paper. Add more flour to the top if you would like. It is not necessary but helps the design stand out better.Using a scoring blade or sharp knife create a design.
Gently place bread with parchment into the preheated Dutch oven. Cover with lid and bake for 30 min. Remove cover and bake an additional 10-15 minutes. This bread browns faster than the plain Dutch Oven Sourdough Bread. Cool on a wire rack for at least 1 hour before slicing. Enjoy!