Preheat oven to 375 ℉. Grease a 9-inch pie plate or round baking dish with oil.
Cook your spaghetti according to package directions. Meanwhile, prep your vegetables. Once the spaghetti is ‘al dente’, drain in a colander then place in a large bowl.
To make sauce, return the pot you cooked the pasta in (or another pot if you prefer) to the stove and heat 2 tablespoons of olive oil over medium-high heat. Add chopped onion and carrot and cook for 2 to 3 minutes.
Add chopped mushroom and saute until the mushrooms begin to brown. Add garlic, 1/2 teaspoon salt, and Italian seasoning and cook for 2 more minutes or until all the vegetables are soft. Stir in spinach and then crushed tomato. Lower heat and simmer while you prepare the spaghetti “crust”.
To the cooked spaghetti, add the remaining tablespoon of olive oil, eggs, parmesan cheese, the rest of the salt, and a few grinds of pepper. Mix well then press the spaghetti mixture into the bottom and up the sides of your pie pan.
Spoon the veggie sauce into the center of the spaghetti. Spread into an even layer, leaving an-inch boarder of spaghetti not covered in sauce. Sprinkle mozzarella cheese over the top.
Bake until cheese is golden brown, 20 to 22minutes. Allow to cool for 5 to 10 minutes, then cut into wedges and serve.