Cook cavatappi according to package directions for al dente, adding around 2 tbsp kosher salt to the pasta cooking water when adding the cavatappi. Reserve 1 cup pasta cooking water prior to draining. Drain the pasta.
Meanwhile, preheat a large pan on medium heat. Add olive oil and mushrooms, and cook for 5-6 min, stirring occasionally. Add salt, pepper, and garlic powder. Stir in cream and once nearly simmering, stir in cheese.
Once melted, stir in cooked pasta, bruschetta, parsley, and spinach. Cook just until spinach wilts, adding in some reserved pasta water to loosen sauce as desired. Serve topped with red chili flakes, if using.
In a small pan over medium heat, add vegan butter. Once hot, add sage leaves and stir until sage leaves are crisp, which takes less than a minute. Top pasta with crispy sage leaves.