My local grocery store was having a sale on cooked, chopped lobster meat, ( it's still expensive, but still a good deal,) so I called my daughter and asked if she would like to share an "adult" mac and cheese dinner. She loves mac and cheese, so I knew she'd say yes, lol. We didn't stop eating it until we were way over stuffed, it was THAT good!
Heat oven to 350. Lightly spray a 9" x 13" casserole pan w/ cooking spray. Cook pasta as directed, drain, put aside in bowl to cool.
In lg, heavy pot, over medium heat, melt unsalted butter. Saute garlic clove and shallot 1 min. Whisk in flour. Slowly whisk in milk until there are no lumps. Add bay leaf and nutmeg. Lower heat to low, simmer for 5 mins. Stir in cheeses, setting aside 1 oz of parm/reggiano mix. Stir until cheese is melted. Turn off burner.
In medium bowl, combine panko crumbs and ritz crackers. Add 1 oz crumbled bacon and reserved grated parm/reggiano cheese mix. Spoon into food processor and pulse until it becomes fine crumbs. Add pasta, lobster and bacon to sauce in lg pot. Mix well. Spoon into casserole pan. Top w/ crumb mix. Drizzle with melted butter. Bake 15-20 mins, or until bubbly and light brown on top.