Step 1

Preheat the oven to 350°F.

Step 2

Slice the zucchini lengthwise into 16 strips that are ⅛ inch wide (you should be able to get 8 strips from each zucchini). Note: The easiest way to do this is to use a mondoline if you have one. If not, carefully cut them by hand using a sharp knife.

Step 3

Lightly spray two large baking sheets with cooking spray (I use two 17¼ x 11½-inch pans). Arrange the zucchini slices on the baking sheets in a single layer (it's okay if they overlap slightly). Season with salt and pepper.

Step 4

Bake for 15 to 20 minutes, flipping the zucchini slices once halfway through, just until they have softened and are pliable enough to roll without breaking. Remove from oven and let sit for a few minutes until they are cool enough to handle.

Step 5

While the zucchini are baking, mix the spinach, ricotta cheese, 1 cup of the mozzarella cheese, ¼ cup of the Parmesan cheese, the egg, dried basil, nutmeg, and some salt and pepper until well-combined.

Step 6

Spread 1 cup of the marinara sauce in a 9x13-inch baking dish.

Step 7

Take one zucchini strip and place it on your work surface. Place a spoonful of the spinach and cheese mixture on the end of the zucchini strip closest to you. Roll up and place seam-side down in the baking dish. Repeat with the remaining zucchini and filling. Note: I pre-divide my filling into 16 portions before I start rolling so that each roll-up will have about an equal amount.

Step 8

Top the roll-ups with the remaining marinara sauce and sprinkle with the remaining ½ cup of mozzarella cheese and ¼ cup Parmesan cheese.

Step 9

Bake, uncovered, for 45 minutes or until the filling is heated through and the sauce is bubbly in the center of the dish as well as around the edges. Note: The zucchini may release some water as they bake. A lot of the excess liquid should evaporate if you allow the roll-ups to bake until bubbly in the center.

Step 10

Remove the baking dish from the oven and allow the roll-ups to rest for 10 minutes before serving.

Step 11

Sprinkle with chopped fresh basil, if desired.