What's that you ask? Oh, just a grated zucchini... Yup. Zucchini.
I use Aldi's Baker's Choice mix for Chocolate Chocolate-Chip muffins ($1.99), prepared according to directions, adding a shredded medium zucchini (3 for $1.79).
Alex enjoys them in mini-muffin form best. No matter the size, they're always really yummy and really moist, thanks to the zucchini.