Prep the zucchini:

1. Preheat oven to 375F.
2. Remove the stems from the zucchinis and use a mandoline slicer or a knife to slice lengthwise into 1/8 inch thick slices (lengthwise, not rounds).
3. Salt both sides of the zucchini slices and place on a plate for 10-20 minutes to allow it to “sweat” or draw out excess moisture. Then, use a paper towel to pat it completely dry.
4. Arrange the zucchini slices in a single layer on a large baking sheet. Drizzle with olive oil. Bake for 20-25 minutes until soft, flipping the zucchinis halfway to achieve even cooking. Set aside.

Make the cheese filling:

1. In a medium mixing bowl, combine ricotta cheese, ½ cup mozzarella, ¼ cup Parmesan, beaten egg, basil, salt, and pepper. Stir well until evenly combined.

Roll up the zucchini:

1. Arrange the zucchini slices on a clean surface or large baking sheet.
2. Carefully spread 1-2 tablespoons of cheese filling on each zucchini slice.
3. Take each filled zucchini slice and roll it up.

Assemble:

1. In a 9x13-inch casserole dish, evenly spread out ½ cup of marinara sauce.
2. Place the rolled zucchini, seam side down, into the casserole dish in a single layer. If there is any extra cheese filling, simply spread on top of the zucchini slices.
3. Spread the remaining 1 ½ cups marinara sauce over the zucchini roll ups.
4. Top with the remaining 1 cup mozzarella cheese and ¼ cup of Parmesan cheese.

Bake the roll ups:

1. Cover the casserole dish with aluminum foil and bake for 25 minutes. Then, remove the foil and bake uncovered for another 10-15 minutes or until the melted cheese turns golden brown and bubbly.
2. Optionally, turn on broiler on high and broil for 2-3 minutes to get a crisper and browner cheesy crust. But keep a close eye on the broiler as things can burn quickly.
3. Let the roll ups cool for 10 minutes. Then, slice and serve with fresh chopped basil on top.