"Create a high-protein, high-fiber muffin recipe using Kirkland Organic Nonfat Greek Yogurt, oats, chia seeds, and protein powder. Increase fiber further with an ingredient like ground flaxseed or extra oats while keeping the muffins moist and chocolatey. Include Trader Joe's dark chocolate chunks. Provide updated estimated macros per muffin and for the full batch. Use imperial units."