Bring 3 qts. water to boil in large pan. Add spaghetti and cook until tender but still firm to the bite, 8-10 minutes. Meanwhile, heat butter and olive oil over medium heat in large skillet. Add garlic and cook until golden. Discard garlic pieces. Garlic should be smashed with the flat side of knife, not minced if you wish lighter garlic flavor. Add shrimp, salt, pepper, and 2 Tblsp. parsley to skillet and cook until shrimp turn pink, 1 to 3 minutes. Remove skillet from heat. Drain cooked spaghetti and add to skillet, along with parmesan cheese. Place mixture in warmed serving bowl and sprinkle with remaining tablespoon parsley. Serve at once with tossed salad and garlic bread.