Soak cashews in a large bowl covered with water for at least 30 minutes, then drain and set aside.
Cook pasta according to package directions.
While the pasta is cooking, heat one tablespoon olive oil in a large skillet. Add shrimp and sauté until cooked through, about 5 minutes. Shrimp will be pink and opaque when it's done. Remove from heat and set aside.
Add garlic, avocados, cashews, olive oil, lemon juice, lemon zest, dill, and dash of salt and pepper to a food processor. Pulse until ingredients are well mixed and the sauce is smooth.
Drain pasta, reserving 2-3 tablespoons of the water.
Combine avocado cashew cream sauce, pasta, reserved water, and shrimp in a large bowl and toss gently until the pasta is coated with the sauce.
Optional: top with grated parmesan cheese, small pieces of additional cut avocado, and/or salt and pepper to taste.