"Create a recipe for real fermented sourdough banana chocolate chip muffins using an existing partially mixed sourdough bread dough base. The user has mixed water, starter, and half of the required flour so far. Explain how to adapt the base into muffins, whether oats can replace some of the remaining flour, and ensure the recipe is truly fermented sourdough (not discard muffins), with a long fermentation/rest so gluten can break down. Include imperial units only. Make it practical, safe, and clear, with notes on how much oats can be used, how to finish the dough, and baking instructions for muffins."