Bring a large pot of salted water to boil, add spaghetti and bring the water back to a rolling boil. Cook pasta until al dente; drain well.
Combine broccoli, mushrooms, butter, salt, pepper, Parmesan cheese, lemon juice, garlic powder and basil in a large saucepan. Heat the mixture over a low heat, stirring often, until the mushrooms and broccoli are hot.
Place the spaghetti and the hot mixture in a large serving dish, toss lightly before serving.