The night before mix flour, starter, water, and oil in a large mixing bowl.
Cover and allow to ferment on counter for 8-24 hours.
The next day, preheat the oven to 350 degrees F.
In a separate bowl, mix the remainder of the ingredients well.
Add the new mixture to the overnight mixture. This will take a minute or 2. Use a whisk and break up the fermented mixture while stirring in the liquid ingredients. Whisk until completely combined.
Prepare 8x8 baking dish by spraying with oil and dusting with flour.
Pour batter into baking dish.
Bake 40-45 minutes or until a toothpick comes out clean.
Allow to cool completely before frosting with your favorite icing.