Preheat the oven to 400°F (200°C). Spread the sugar-free marinara sauce evenly over the bottom of a 9x13-inch baking dish.
Using a mandolin or vegetable peeler, slice each zucchini lengthwise into long, thin strips about paper-thin.
Lay the zucchini strips in a single layer and generously sprinkle with salt; let sit a few minutes to draw out moisture, then press each strip dry with paper towels.
In a large bowl, combine the ricotta, cream cheese, shredded mozzarella, grated Parmesan, eggs, dried Italian seasoning, garlic powder, and crushed red pepper; mix until smooth and well combined.
Place one zucchini strip on a paper towel, pat dry again if needed, then spoon about 2 teaspoons of the cheese mixture onto one end of the strip.
Roll the zucchini strip tightly around the filling and place the roll seam-side down in the prepared baking dish on top of the marinara, continuing until the dish is filled.
Bake the roll ups in the preheated oven for 25 minutes, until the cheese is bubbly and golden at the edges.
Remove from the oven and let sit a few minutes before serving warm.