Cook macaroni according to package instructions. Drain and set aside. In a skillet over medium heat, add butter and melt. Stir in flour until smooth. Slowly whisk in half-and-half. Bring to a boil, stirring constantly. Once thickened (about 2 minutes), reduce heat to low and add in cheese. Stir until cheese is melted. Stir in salt, pepper, seasonings, and pimentos. Add macaroni and stir until combined. Top with crumbled bacon and chopped parsley.