1-First, heat the 4 tablespoons of olive oil in a large skillet over medium heat. Add the 1 cup of chopped onion and cook until softened, about 5 minutes, to build a solid flavor base for your sauce.

2-Next, add the 2 medium chopped zucchini, 2 medium chopped yellow squash, 3 minced garlic cloves, 1/2 teaspoon of dried oregano, 1/4 teaspoon of red pepper flakes, and a pinch of salt, then cook until the vegetables soften, around 5-7 minutes.

3-Stir in the 2 tablespoons of tomato paste and cook for a minute to deepen the flavors. Then, add the 1 can (28 ounces) of whole peeled tomatoes, breaking them into pieces as they simmer, along with the 1 jar (12 ounces) of roasted red peppers and 2 to 3 teaspoons of mushroom powder if using.

4-Meanwhile, cook the 12 ounces of spaghetti in a large pot of boiling salted water until al dente, following package instructions, usually 8-10 minutes. Once done, drain the pasta and set it aside.

5-Remove the sauce from heat and stir in the 5 cups of spinach leaves and a handful of fresh basil leaves until wilted. Toss the cooked pasta with the sauce, season with salt and freshly ground black pepper to taste, and serve topped with Parmesan cheese or nutritional yeast for a personalized touch.