Pat cauliflower florets dry using paper towels and reserve.
Place the flour in a shallow bowl.
In a medium saucepan, warm the milk and cornstarch over moderately high heat; let it cook for about 5 minutes, until slightly thickened: let it cool and transfer the mixture to another shallow bowl.
In a third shallow bowl, place breadcrumbs.
Dip the cauliflower florets in the flour, then into the milk mixture; roll them over the breadcrumbs.
Brush cauliflower florets with olive oil and transfer them to the Air Fryer cooking basket.
Cook at 400 degrees F for about 10 minutes, shaking the basket halfway through the cooking time.
To make Buffalo sauce, melt the butter in a saucepan over medium-high heat; turn the heat to a simmer and add in the remaining sauce ingredients. Cover and continue to simmer, until cooked through.
Pour the sauce over air-fried cauliflower florets and serve immediately.