Combine sourdough starter and 300 grams of lukewarm water in a bowl and stir to break up starter.

In a large mixing bowl, add whole wheat flour, all purpose flour, cinnamon, raisins, salt, and sugar. Pour the sourdough starter/water mixture into the bowl of flour and mix until combined. Cover with plastic wrap and allow to rise for at least 12-18 hours. The dough should double in size.

Dust a work surface with flour and remove the dough from the mixing bowl. Gently stretch the edges of the dough and fold them into the center of the dough, creating a loaf shape. Do this gently for about 6 pulls and then add to a banneton or bowl to proof for another 2 hours with the seam facing up.

Preheat the oven to 475 degrees Fahrenheit. Add dutch oven with the lid into the oven to heat for 30 minutes.

Cut a piece of parchment paper and place onto the counter top. Spray with oil and add dough to parchment paper. Grab parchment paper and add to dutch oven. Cover with lid and bake for 30 minutes. Then remove the lid and bake for an additional 15 minutes.

Allow the bread to cool for at least 30 minutes to an hour.