2/3 cup (about 2 1/2 ounces) grated Parmigiano-Reggiano cheese
1/2 teaspoon salt
2 tablespoons chopped fresh parsley
1/2 teaspoon freshly ground black pepper
Cook pasta according to package directions, omitting salt and fat. Drain in a colander over a bowl, reserving 1/4 cup cooking liquid.
While pasta cooks, cook bacon in a large nonstick skillet over medium-high heat 4 minutes or until crisp, stirring occasionally. Remove bacon from pan, reserving drippings. Add garlic to drippings in pan; sauté 1 minute, stirring constantly. Sprinkle flour over garlic; cook 30 seconds, stirring constantly. Gradually add milk, stirring constantly; cook 2 minutes or until bubbly and slightly thick, stirring constantly. Reduce heat to low. Gradually add cheese, stirring until cheese melts. Stir in salt and reserved 1/4 cup cooking liquid. Add hot pasta to pan; toss well to combine. Sprinkle with bacon, parsley, and pepper.