Preheat the oven to 350 degrees F.
In a pan over medium-high heat, add the butter and whisk until melted.
Slowly add in the flour while continuing to whisk until they are fully combined.
4, Add in the whole milk and whisk until combined. Keep whisking the mixture for 2-3 minutes until it begins to thicken.
Add in the spices and continue to whisk until the sauce is creamy and thick.
Lower the heat to medium-low and add in the sour cream and cheeses, followed by the hot sauce, chicken, and pasta. Stir until combined.
Pour the buffalo chicken mac and cheese mixture into a greased casserole dish.
For the breadcrumbs: in a medium saucepan, melt the butter and olive oil.
Add in the breadcrumbs and stir until combined.
Sprinkle the breadcrumb topping over the buffalo chicken mac and cheese and bake for 20 minutes. You can put the oven on broil for an additional few minutes to make sure the topping is golden brown.
Sprinkle parsley if desired and allow to cool completely before serving.