1. In a large pot of boiling salted water, cook pasta for about 11 min or until al dente, or according to package directions.
2. Meanwhile, in a large pot, melt butter over medium heat. Add garlic, thyme, salt and hot pepper flakes. Cook 1 min. Sprinkle with flour; cook, whisking, for 1 min. Gradually whisk in milk. Bring to a boil and reduce heat. Whisk for 3 to 5 min or until smooth and thickened.
3. Drain pasta and return to pot. Pour in sauce; toss, stirring for 1 to 2 min over medium heat to coat the pasta. Stir in Bocconcini, basil and salt to taste, if needed. Serve with grated Parmesan.