Muffin mixes are pre-made blends of dry ingredients like flour, sugar, and baking powder, designed to simplify muffin preparation. Just add wet ingredients such as eggs, milk, and oil, then mix and bake for freshly made muffins with ease and convenience. They come in various flavors, including blueberry, chocolate chip, and banana, allowing for delicious homemade treats without the hassle of measuring multiple ingredients.