Drain your cashews and add them to your blender, along with all remaining sauce ingredients. Process on high until smooth and creamy.
Add your spiralized sweet potatoes in a large skillet with a tablespoon or two of water and sauté over medium heat until softened, approx 5 minutes. Adding more water if needed to prevent sticking. Then add your spinach and mix well until wilted, about 30 seconds. Turn off heat, then pour the sauce over your noodles and serve.
Notes
The sauce will thicken as it cools, so if you're working ahead, you may need to add more water before serving.Tastes best same day, but you may store leftovers in the refrigerator for 1-2 days.