Preheat the oven to 425°F. and line a baking sheet with aluminum foil. Place the chopped vegetables on the sheet and toss with olive oil and salt and pepper. Roast for 20 minutes until the vegetables are soft and golden brown. Remove the vegetables from the oven and reduce the heat to 375°.
In a medium bowl add the ricotta, egg, Parmesan Romano, lemon, garlic, oregano, red pepper flakes, salt and pepper. Stir together until the egg is incorporated. Add the chopped basil and fold in until mixed thoroughly. Set aside.
In a large pot of boiling water, boil the noodles until al dente according to the package.
Drizzle the bottom of a 8x12 pan with olive oil. Spread one cup of the marinara sauce on the bottom of the pan. Layer 4 lasagna noodles on the bottom of the pan. Spread half of the lemon basil ricotta on top of the noodles. Top with half of the roasted vegetables, half of the spinach and 2/3 cups of the marinara sauce. Top with 4 additional noodles, and then the remaining ricotta, vegetables, spinach and 2/3 cup of sauce. Top with 4 more noodles, the remaining sauce and shredded smoked mozzarella cheese.
Bake the lasagna at 375° for 25-30 minutes. The top will be brown and bubbly. Remove the lasagna from the oven and let it sit for 15 minutes before cutting. Garnish the lasagna with basil leaves right before serving.