Yes, you can substitute part or all of the all-purpose flour with whole wheat flour or other alternatives like almond flour or oat flour for a healthier twist. Keep in mind that the texture and flavor may vary.

Yes, you can reduce the sugar if you prefer muffins with less sweetness. You can experiment with using less sugar or even try natural sweeteners like honey or maple syrup, but this may affect the texture and moisture of the muffins.

To prevent muffins from sinking, ensure you don't overmix the batter and avoid opening the oven door too early in the baking process. Also, make sure your leavening agents (baking powder and baking soda) are fresh and not expired.

Yes, you can make gluten-free banana bread muffins by using a gluten-free flour blend or almond flour. Be sure to check that all your ingredients are gluten-free, including any add-ins like chocolate chips or nuts.

If you don't have muffin liners, you can grease the muffin tin well with cooking spray, butter, or oil to prevent sticking. I often use parchment paper cut into squares.

Yes, you can adapt this recipe to make mini banana bread muffins. Simply adjust the baking time, as mini muffins will bake faster than standard-sized ones.