Preheat your oven to 400°F (200°C).
Toss the zucchini, bell peppers, and mushrooms with olive oil, salt, and pepper. Spread them on a baking sheet and roast for 20 minutes.
Cook the gluten-free lasagna noodles according to the package instructions. Drain and set aside.
In a mixing bowl, combine ricotta cheese and chopped spinach.
Spread a thin layer of marinara sauce on the bottom of a baking dish. Place a layer of lasagna noodles on top.
Spread a layer of the ricotta-spinach mixture over the noodles, followed by a layer of roasted vegetables, marinara sauce, mozzarella, and parmesan cheese. Repeat the layers until all ingredients are used, finishing with a layer of cheese on top.
Cover the baking dish with aluminum foil and bake for 40 minutes. Remove the foil and bake for an additional 10-15 minutes until the cheese is bubbly and golden.
Let the lasagna rest for 10 minutes before serving.