Preheat oven to 400 degrees. In a medium skillet add in 3 tbsp olive oil, 1/2 yellow onion & 3 cloves garlic minced. Let it sauté for 2 minutes on medium heat. Then add in our chopped zucchini, chopped red pepper and sliced mushrooms. Toss to coat in the olive oil, garlic & onion mixture.
Sprinkle the salt, basil, garlic powder, onion powder, pepper & cayenne on top. Sauté for 2 minutes. Then with spatula fold in your chopped fresh spinach for 1 minute. Then take off heat & set aside.
In large 9 X 13 baking dish, spray with olive oil. Then pour 2 cups of your sauce of choice at the bottom of your dish, spread out evenly with the back of your measuring cup. Then pour your veggie mixture on top of the sauce evenly. After, toss the veggie mixture into the sauce a little bit. Sprinkle 1/2 cup of cheese over it.
Next place your frozen raviolis in a layer over the sauce & veggies. You don't want them completely overlapping each other, but a little overlap is totally normal. Then evenly pour the remaining sauce over the tops of the ravioli. Spread with spatula to get even if needed.
Cover with aluminum foil and place in the oven at 400 degrees for 25 minutes. Take the aluminum foil off at 25 minutes, sprinkle the remaining cheese on top and then place back in the oven for 20 more minutes uncovered.
Then serve with a big salad or loaf of bread, enjoy!