Rinse the cashews than soak them overnight (or at least 2 hours) in a jar covered by 2 inches of water.
Drain the cashews and process them together in your blender with the roasted red peppers, nutritional yeast, tapioca and water until silky smooth and creamy. Add a little extra water if needed.
Transfer the sauce to a pan and stir in the grated garlic and pepper flakes. Taste and adjust seasonings with a pinch of sea salt and more pepper flakes to your liking. Bring to a simmer on medium flame and cook a few minutes until thick and creamy to your liking.
Meanwhile cook the pasta according to direction on the package, until al dente. In the last minute of cooking add the spinach and cook until wilted. Reserve 1 cup of the cooking pasta water then drain the pasta in a colander.
In a large mixing bowl combine together the pasta, spinach and roasted pepper sauce. Add some of the reserved pasta water if you like to thin out the sauce. Serve warm or cold.
Notes
I've also made this with the Beyond Meat Italian sausage and it was a total hit. Definitely try that on a night you'd like to indulge a bit.