Cook pasta in salted boiling water until tender. Drain, rinse and cool. Set aside.
Pour cream in heavy-bottomed saucepan set over medium heat and warm slowly, stirring. Do not boil. When cream is hot, gradually whisk in 12 oz of the cheese. Whisk in mustard, Worcestershire, pepper, cayenne and salt. Remove from heat.
Set pasta in large bowl. Pour cheese sauce over pasta and toss well to combine. Taste and adjust seasonings if needed.
Preheat oven to 350° F.
Butter bottom of high-sided baking dish. There should be at least 1 inch of space at top of dish after pasta mix is added. Pour cheese and pasta mixture into dish. Top with remaining 4 oz of cheese.
Cover and bake in preheated oven 40 minutes or until bubbling and golden brown.
Makes: 6