Muffins freeze well for up to 3 months. Reheat in microwave for a quick snack., Store in an airtight container at room temperature for up to 2 days or in the refrigerator for a few more days—bring to room temperature before serving., Batter can be made the night before and baked fresh in the morning., Add shredded zucchini or carrots to include more veggies., Substitute bananas with applesauce for moisture and sweetness., Add 1/4 cup chopped walnuts or pecans for a nutty flavor (check for allergies)., For gluten-free muffins, use oat and almond flour blend but expect different texture., Replace chocolate chips with raisins or dried cranberries if desired., To make vegan, use a flax egg (1 tbsp ground flaxseed + 3 tbsp water), and swap milk and oil for plant-based alternatives.