Spray a 9x13 baking dish with cooking spray and preheat oven to 350°.
In a large pot boil water and cook elbow macaroni per package directions for al dente.
Drain macaroni, return to pan and add 2 tablespoons of butter, stir well to keep the noodles from sticking.
Melt remaining butter (6 tablespoons) in large skillet over low/medium heat. Add flour and whisk to combine. Let cook for about 1-2 minutes. Slowly add half and half while continuing to whisk, add milk and whisk.
Add salt, pepper, paprika, Cajon seasoning, whisk. Cook, stirring/whisking consistency, for 4-6 minutes until thickened to a cream consistency.
Remove from heat, add cheese and stir.
Pour cheese mixture into macaroni, stir well.
Dump macaroni into prepared baking dish. Top with remaining cup of Sharp cheddar cheese.