Preheat your oven to 350°F (175°C). Gather ingredients to streamline the assembly process.

Cook the thinly sliced zucchini in a skillet over medium heat for about 8-10 minutes until tender. Set aside to cool.

Sauté fresh spinach in the same skillet for 2-3 minutes until just wilted, then squeeze out excess moisture and set aside.

In a mixing bowl, combine ricotta cheese, grated Parmesan, a beaten egg, minced garlic, chopped basil, parsley, and crushed red pepper. Mix thoroughly and fold in sautéed spinach.

Spread about ½ cup of marinara sauce evenly in a greased casserole dish.

Layer gluten-free noodles atop the marinara, followed by cooked zucchini, half of the cheese mixture, and a sprinkle of mozzarella. Pour ⅓ of the marinara sauce over these layers.

Repeat the layering with another layer of noodles, remaining zucchini, the rest of the cheese mixture, and more mozzarella. Finish with a final layer of noodles, remaining marinara, and mozzarella.

Cover with foil and bake for 30 minutes. Remove foil in the last 5-10 minutes to create a golden top.

Let the lasagna cool for about 15 minutes before slicing and serving.