Preheat oven to 350°F
Cook pasta in a large pot until firm, few minutes less than recommended box directions. Once cooked, drain and set aside.
In a large pot melt butter and sprinkle in flour. Whisk on medium low heat for 3-5 minutes until slightly browned and cooked then add in milk.
Whisk milk and roux together constantly until thicken, about 5-10 minutes, add in salt. Mix together then take ¼ cup of sauce and slowly add into whisked egg while constantly whisking so as not to cook the egg. Once sauce is fully incorporated into egg, whisk this egg mixture into sauce on stove. Stir until smooth
Add freshly grated cheese, of your choice, into sauce (setting aside some for topping). Mix until cheese is melted then add in sriracha, mustard, ground black pepper, and salt, to taste. Taste for seasoning make sure it is not underseasoned!
Fold macaroni into cheese sauce until fully coated. Tip macaroni and cheese into deep 8x8 or 9x13 baking dish and top with extra cheese and seasoned breadcrumbs.
Place on middle rack of oven and bake for 20-25 minutes until lightly golden brown. After this broil on high for 2 minutes until cheese is bubbling and it is golden brown.
Remove from oven and allow to cool for a few minutes before serving.
Enjoy!