In a large bowl, add starter and water. Stir until the starter dissolves into the water. Then add oil and stir.
Add honey and stir until completely dissolved. This may take a few minutes.
Add salt and stir.
Now add your flour. Using your hands, stir the flour into your sourdough mixture. It will be very sticky, but just keep mixing until the flour is fully incorporated. Then let the dough rest on the counter for 15 minutes.
Now we will do our first stretch and fold. I like to have a small bowl of flour next to me to flour my hand with because this dough is incredibly sticky to start out. Grab the edge of the dough and pull it upwards until you feel resistance, and then gently push it into the center. Rotate the bowl and repeat the process until each edge has been stretched and folded in a few times. Continue to flour your hand as needed. Cover and let rest for 30min-1hr.
Repeat step 5 three more times for a total of 4 stretch and folds. On the final (fourth) stretch and fold, add the raisins to the dough as you are working the dough to fully incorporate them.
Cover the dough and allow it to rest (ferment) in a warm room or sunny window for 6 hours.
Get out 2 large loaf pans, or 3 regular ones, and butter and flour them. Set aside.
On a clean countertop, remove the dough from the bowl with a bench scraper. It will still be fairly sticky. Cut the dough into halves (for two large loaves) or thirds (for three regular loaves).
Lightly flour your hands and the top of the first section of dough. Gently flatten the dough out into a rectangle about an inch thick. Now generously sprinkle the top of the dough with cinnamon. You want to cover the entire top with cinnamon, somewhere around 2-4 Tbsp. Then sprinkle additional raisins on top of that.
Using your bench scraper, gently roll the dough into a log (like you would a cinnamon roll). Make sure the roll is fairly tight. Then place the dough into the bread pan and cover with plastic wrap. Repeat this process with the remaining dough. Allow all loaves to rest for 2 hours or until risen to the top of the bread pan.
Preheat your oven to 400 degrees Fahrenheit and bake for 30-35 minutes until golden brown. Optional: Rub butter over the top of your warm loaves to keep the crust soft. Remove bread from pans and allow to cool for two hours on cooling racks. Enjoy!