Step 1: Combine the refried beans, Rotel tomatoes, and taco seasoning. Spread the mixture in a 7 x 11-inch casserole dish.
Step 2: Mash the avocado. Mix in the lime juice, garlic, cilantro, onion powder, salt, and cayenne. Spread it over the bean layer.
Step 3: Carefully spread the sour cream over the avocado layer. Top with the finely shredded cheese, black olives, tomatoes, and green onions. Cover and refrigerate until ready to serve.