Preheat the oven to 425 degrees Fahrenheit.

Bring a large pot of water to a boil salt it well. Cook the ziti according to package instructions until al dente. Drain and set aside.

In a medium bowl, combine the ricotta, garlic, lemon zest, Italian seasoning, chopped sun-dried tomatoes, salt, and pepper. Stir well and set aside.

Heat the olive oil in a large skillet over medium heat. Remove the sausage from its casing and cook, breaking it up with a spoon, until browned and cooked through. Transfer to a plate and set aside.

Using the same large pot you cooked the pasta in, add the fresh spinach over medium heat and cook just until wilted. Remove from the heat and let cool slightly. Transfer the spinach to a clean tea towel and squeeze out as much moisture as possible, then roughly chop and set aside.

Return the cooked pasta to the pot. Add the marinara sauce and cooked sausage and stir until the pasta is evenly coated.

To assemble, spread half of the pasta mixture into a greased casserole dish. Dollop the ricotta mixture evenly over the pasta and scatter about ¾ of the chopped spinach on top. Add the rest of the pasta mixture, followed by the remaining spinach. Sprinkle generously with the mozzarella and parmesan.

Bake uncovered for 25 minutes, or until bubbly and the cheese is melted and lightly golden. Remove from the oven, garnish with fresh basil if using, and serve warm.