Preheat the oven to 400°F (200°C). Line a baking sheet with parchment.

Toss zucchini, red bell pepper, yellow squash, and mushrooms with olive oil, 1/2 tsp salt, and a few grinds of black pepper. Spread in one layer.

Roast for 20–25 minutes, flipping once halfway, until the vegetables are lightly caramelized and most moisture has evaporated. Remove and set aside.

In a medium bowl, combine ricotta, minced garlic, Italian seasoning, and a pinch of salt. Stir until smooth.

Reduce oven temperature to 375°F (190°C). Spread a thin layer (about 1/2 cup) of marinara on the bottom of a 9×13-inch baking dish to prevent sticking.

Place a layer of lasagna sheets over the sauce. Add half of the roasted vegetables, dollops of the ricotta mixture spread evenly, and sprinkle with mozzarella and a light dusting of Parmesan.

Repeat: sauce, noodles, remaining vegetables, remaining ricotta, mozzarella, and Parmesan. Finish with a generous final layer of mozzarella and Parmesan.

Cover tightly with foil and bake for 30 minutes at 375°F (190°C).

Remove the foil and bake for another 10–15 minutes, until the cheese on top is golden and bubbling.

Let the lasagna rest for at least 10 minutes before slicing. Garnish with torn fresh basil leaves and serve.