Step 1: Prepare the Zucchini Ribbons
Wash and dry the zucchini. Trim off both ends. Using a mandoline slicer set to about ⅛-inch thickness, or a sharp knife, carefully slice the zucchini lengthwise into long, thin ribbons. You want them thin enough to be flexible but thick enough to hold the filling without tearing – about the thickness of lasagna noodles. Aim for 12-15 slices total. Lay the zucchini slices on paper towels or clean kitchen towels, sprinkle both sides with salt, and let sit for 10-15 minutes to draw out excess moisture.

Step 2: Make the Cheese Filling
While the zucchini drains, prepare the filling. In a large mixing bowl, combine ricotta cheese, 1 cup of the shredded mozzarella (reserve ½ cup for filling and 1 cup for topping), Parmesan cheese, beaten egg, minced garlic, Italian seasoning, salt, pepper, and fresh herbs if using. Mix thoroughly until all ingredients are well incorporated and the mixture is smooth and creamy. Taste and adjust seasoning if needed.

Step 3: Prep the Baking Dish
Preheat your oven to 375°F (190°C). Spread 1½ cups of marinara sauce evenly across the bottom of a 9×13-inch baking dish. This creates a flavorful base that prevents sticking and adds moisture during baking.

Step 4: Pat Dry the Zucchini
After the zucchini has released its moisture (you’ll see water pooling on the towels), pat each slice thoroughly dry with fresh paper towels. Removing this excess moisture is crucial to prevent watery roll ups. The drier the zucchini, the better the final texture.

Step 5: Assemble the Roll Ups
Lay one zucchini ribbon on a clean work surface. Spread about 2-3 tablespoons of the cheese filling evenly along the entire length of the zucchini slice, leaving a small border at the edges. Starting from one end, gently roll up the zucchini slice, keeping the filling inside. The roll should be snug but not so tight that filling squeezes out. Place the roll seam-side down in the prepared baking dish. Repeat with remaining zucchini slices, arranging all roll ups in the dish so they fit snugly but not too crowded.

Step 6: Add Sauce and Cheese
Spoon the remaining 1½ cups of marinara sauce over and around the zucchini roll ups, making sure each one gets some sauce coverage. Sprinkle the reserved 1 cup of mozzarella cheese evenly over all the roll ups, followed by the 2 tablespoons of Parmesan cheese. The cheese should cover most of the top surface.

Step 7: Bake Covered
Cover the baking dish tightly with aluminum foil (spray the underside with cooking spray to prevent cheese from sticking). Bake in the preheated oven for 20 minutes. This covered baking ensures the zucchini cooks through and the cheese melts without the top over-browning.

Step 8: Finish Uncovered
Remove the foil carefully (watch for steam) and return the dish to the oven. Bake uncovered for an additional 10-15 minutes, until the cheese is golden and bubbly and the zucchini is tender when pierced with a fork. If you want extra browning on the cheese, turn on the broiler for the last 2-3 minutes, watching carefully to prevent burning.

Step 9: Rest and Serve
Remove from oven and let the roll ups rest for 5 minutes before serving. This allows the cheese to set slightly and makes serving easier. Garnish with fresh basil leaves and a sprinkle of red pepper flakes if desired. Serve 2-3 roll ups per person with extra marinara sauce on the side if desired.