Cook elbow macaroni to al dente, drain and set aside.
Heat a deep skillet over medium heat, then add olive oil and butter.
After the butter melts, add flour a little at a time while whisking. Cook flour through, around 2-3 minutes.
Add milk slowly while whisking and bring to boil while whisking.
Allow milk to thicken a bit, then add 2 cups of cheese, a little at a time while stirring until all cheese has been added.
Add cayenne pepper and stir, then add cooked macaroni to sauce.
Evenly distribute sauce and macaroni, then move to a deep baking dish.
Add remaining cheese to the top and broil under brown and crispy.