Preheat oven to 350 F. Lightly grease a deep 9" square baking dish.
Heat the oil in a large skillet over medium heat and add in the onion. Saute until it starts to soften, then add in the mushrooms and zucchini. Cook for an additional 4 minutes, then add the garlic for another 30 seconds. Set aside.
In a bowl, mix together the ricotta, spinach, egg, pepper and salt.
Layer 1: Add about 1/2 cup of the sauce to the bottom of the greased dish. Add 1 matzo cracker, then about 1/3 of the ricotta mixture, 1/3 of the veggies, about a cup of the sauce, and 1/4 of the cheese.
Layer 2: Repeat with matzo, ricotta, veggies, sauce, cheese.
Layer 3: Repeat with matzo, ricotta, veggies, sauce, cheese.
Layer 4: Finish with the remaining matzo, sauce and cheese.
Cover in foil that has been greased to prevent the cheese from sticking, then bake for about 40 minutes. Remove the foil and increase the heat to broil. Broil for 5 minutes or until bubbly and golden. Allow to sit before cutting into squares and topping with basil, if desired.