Slice the zucchini to 1/16"-1/8" thick strips with a wide vegetable peeler or mandoline. Once the seeds are mostly showing, cut strips from the other side. The center 1/2" with mostly seeds should not be used and can be saved for another purpose. Layer the zucchini strips in a colander and sprinkle kosher salt on each layer. Let the zucchini release water for 60-90 minutes.
Meanwhile, cook the spinach in the microwave for 60 seconds, then when able to handle, squeeze the spinach in a clean kitchen towel to remove moisture. Give the spinach a chop.
Combine the spinach with the ricotta, basil, parsley, 3/4 cups mozzarella, 1/4 cup Pecorino Romano, and a half teaspoon of pepper. Mix well and taste test. Adjust salt levels to desired taste and then add 2 beaten eggs and mix to combine.
Rinse the zucchini to remove the excess salt and dry off thoroughly with paper towels.
On a large clean surface layer 3-5 pieces of zucchini lengthwise overlapping each other. Place 2-3 tablespoons of the ricotta mixture in the middle of the zucchini layers. Roll up the zucchini rollatini and leave the seam side down. Work in batches until all the zucchini is used up.
Layer a half inch of marinara sauce into the bottom of a large baking dish. Place all the zucchini rollatini, seam side down, into the baking dish. Spoon some more of the sauce onto each rollatini and sprinkle with the remaining mozzarella and Pecorino Romano cheese.
Bake at 400f for 20-30 minutes or until bubbly and golden on top. Enjoy!