While my boys favorite muffins are Peanut Butter Banana Chocolate Chip Muffins, my favorite gluten-free muffins are these Apple Streusel Muffins. These muffins perfectly combine the flavors of cinnamon, butter, and apple and are topped with a cinnamon streusel topping. I enjoy eating these year-round, using whatever tart apples I can find at the store.