The day before or 8-24 hours before, mix the following ingredients in the bowl of the Stand Mixer, sourdough starter, honey, room temperature butter, and flour.
Place the dough in a greased bowl, cover with a beeswax sheet or plastic wrap.
The next day (or 12-24 hours later)...
Preheat oven to 350 degrees F. Grease a bread baking pan.
Check the firmness of the dough. If it feels to hard to work, place it in the preheating oven for 3-5 minutes. This should soften the butter and honey enough to be able to work in the remaining ingredients.
Place the dough in the bowl of a stand mixer, and attach the paddle attachment.
Add the eggs and vanilla, and mix on low to medium speed until mostly incorporated.
Add the remaining ingredients, pumpkin puree, brown sugar, pumpkin spice, salt, and baking soda.
Pour into the greased baking pan, and add your toppings (optional).
Bake for 55-60 minutes or until the center is fully cooked.
Poke a fork or chopstick in the center. If it comes out clean the center is cooked, if it comes out with gooey batter stuck to it, it needs another 5-10 minutes of cooking time.
Let cool for 20 minutes before serving to prevent the loaf from falling apart.