"Create a precise fermented sourdough banana chocolate chip muffin recipe based on this existing dough base: 325 g water, 100 g starter, and 253 g of 485 g flour already mixed. The user wants exact amounts for finishing the recipe using the remaining flour, with the option to replace some of the remaining flour with oats. Make it a true fermented sourdough muffin recipe with a long fermentation/rest so gluten breaks down, not discard muffins. Use imperial units only in the final recipe, but you may internally account for the gram-based base. Include clear guidance on how much of the remaining flour can be swapped for oats, and keep the recipe practical and accurate."