In a large bowl mix together ricotta, 3/4 cup Parmesan, egg yolk, basil, crab, and salt and pepper .
Preheat oven to 350 degrees. Fill the manicotti shell with the crab mixture and place in a buttered baking dish. top the filled shells with the Béchamel Sauce and sprinkle with the remaining Parmesan cheese. Bake until bubbly and the top is golden brown, about 115 to 20 minutes. Serve immediately.