Cook the lasagna noodles according to package instructions in a large pot of salted boiling water until al dente. Drain and lay them flat on a clean kitchen towel.
In a large skillet, drizzle a bit of olive oil over medium heat. Add the minced garlic and sauté for about 1 minute until fragrant. Then, add the zucchini, carrot, bell pepper, and spinach. Cook for about 5-7 minutes until the vegetables are tender. Season with oregano, basil, red pepper flakes (if using), salt, and pepper. Remove from heat and set aside to cool slightly.
In a large bowl, combine the ricotta cheese, half of the mozzarella, and half of the Parmesan. Stir in the sautéed vegetables and mix until well combined. Taste and adjust seasoning if necessary.
Take a cooked lasagna noodle and spread about 0.25 cups of the cheese and veggie mixture along the length of the noodle. Carefully roll the noodle up from one end to the other, ensuring the filling is secured inside. Place the rolled lasagna seam-side down in a greased baking dish. Repeat with remaining noodles.
Preheat your oven to 375 degrees F (190 degrees C). Pour half of the marinara sauce over the lasagna rolls, spreading it evenly. Sprinkle the remaining mozzarella and Parmesan cheese over the top of the rolls, and finish with the rest of the marinara sauce.
Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes. Then, remove the foil and bake for an additional 15-20 minutes, or until the cheese is bubbly and golden brown.
Remove the lasagna roll from the oven and let it sit for about 10 minutes. Garnish with fresh basil leaves before serving.