Cook rigatoni pasta according to package directions until al dente.
Preheat your broiler. Toss cherry tomatoes with 1 tablespoon olive oil, salt, and pepper on a baking sheet. Broil for 10-15 minutes until blistered and juicy.
While the pasta cooks and tomatoes broil, blend sauce ingredients: cashews, 1/4 cup olive oil, 1 1/2 cups water, 1 large roasted red pepper, 1 clove garlic, and 2 tablespoons nutritional yeast in a blender until very smooth and creamy.
Drain the cooked pasta, reserving about 1/2 cup of the pasta water.
Pour the creamy red pepper sauce over the hot pasta (off the heat). Stir well to coat every piece. If the sauce is too thick, add a splash of the reserved pasta water until it clings beautifully.
Serve immediately, topping the pasta with the blistered tomatoes. Garnish with fresh herbs, extra salt, and pepper if desired.