Heat the oven to 375°F. Lightly grease 8 cups of a standard muffin tin with the olive oil.
In a large bowl, combine the ground turkey, squeezed-dry zucchini, breadcrumbs, Parmesan, egg, 2 tablespoons of the marinara, Italian seasoning, minced garlic, salt, and black pepper. Mix gently until just combined.
Divide the mixture among the 8 greased muffin cups. Press it in lightly, leaving the tops level rather than packing the mixture tightly.
Bake until the muffins are cooked through and reach 165°F in the center, about 20 to 25 minutes.
Spoon the remaining marinara over the muffins. Let them rest in the tin for 5 minutes, then loosen the edges and lift them out to serve.