1. Cook spaghetti in boiling salted water until tender. Drain.
2. Heat soup, stirring until smooth; add butter and milk.
3. When hot remove from heat and stir in grated cheese, saving some to sprinkle on top.
4. Combine cheese sauce with spaghetti, crab meat and pepper.
5. Place in greased shallow casserole and sprinkle with remaining cheese.
6. Bake in hot oven (400°F.) about 30 minutes.