Preheat the oven to 425°F (220°C).

Trim the ends from the zucchini. Using a mandoline or a sharp knife, carefully slice each zucchini lengthwise into approximately 1/8-inch-thick strips.

Arrange the zucchini slices in a single layer on baking sheets. Sprinkle them lightly with salt and allow them to sit for about 5 minutes so they release some of their excess moisture.

Place the zucchini in the oven for about 1 minute, just long enough to begin softening the slices. Thicker hand-cut slices may require a few extra minutes. Remove them from the oven and thoroughly pat away excess moisture with paper towels.

In a medium bowl, combine the ricotta, 1/2 cup Parmigiano Reggiano, basil, parsley, garlic, egg, salt, and black pepper. Stir until evenly combined.

Spread approximately 1/2 cup of marinara sauce over the bottom of a large baking or casserole dish.

Slightly overlap two zucchini slices to make a wider strip. Spread about 1 tablespoon of ricotta filling over the zucchini, then gently roll it up. Place the roll seam-side down in the prepared baking dish.

Continue filling and rolling the zucchini until all the filling has been used. Arrange the zucchini ricotta rolls snugly in the baking dish.

Spoon 1–2 tablespoons of tomato sauce over each roll. Sprinkle the mozzarella and remaining 1/2 cup Parmigiano Reggiano evenly over the top.

Bake the Zucchini Rollatini uncovered for 25–30 minutes, or until the zucchini is tender and the cheese is melted, bubbling, and lightly browned.

Let the rollatini rest for about 5 minutes before serving. Garnish with additional fresh basil if desired.