Prepare the cashew cheese: in a high-speed blender add the cashews, water, garlic, nutritional yeast, lemon juice, tapioca starch, onion powder and salt. Blend until smooth and creamy.
Drizzle the olive oil in a large deep skillet and bring to medium heat. Add the onion, bell peppers and sea salt. Cook until softened, about 10 mins. Add the vegan ground "beef" and cook, stirring often until browned, about 5 mins. Pour in the tomato sauce and bring to a low simmer.
Pre-heat oven to 375F/190C. Bring a large pot of water to a boil and add the ziti noodles. Cook until almost al-dente, about 6 mins (they should be just undercooked as they will continue cooking in the oven). Strain and add back to the pot. Scoop 1 cup of the tomato sauce and mix to combine.
Assemble the Ziti! Scoop 1 ½ cups of the tomato sauce into a large casserole dish (8x11 inches). Smooth with a spatula into an even layer. Next add the noodles, followed by the remaining tomato sauce, and finally drizzle with the cashew cheese to cover. To finish, sprinkle with the shredded cheese.
Place a baking tray on the bottom rack to catch any overspill, if any, and bake for 25 minutes until the cheese is melted and golden around the edges.