Melt the unsalted butter in a small saucepan over low heat until just liquefied, 1–2 minutes.
Whisk in the honey and Dijon mustard until smooth and fully emulsified, 1 minute.
Add the apple cider vinegar, garlic powder, kosher salt, black pepper, and cayenne pepper. Whisk to combine.
Bring to a gentle simmer over low heat and cook, whisking occasionally, until glossy and slightly thickened, 2–3 minutes; the sauce should coat the back of a spoon.
Taste and adjust seasoning, adding a pinch more salt for balance or a splash more vinegar for brightness if desired.
Use warm to toss with hot, cooked wings until evenly coated, or cool 10 minutes and refrigerate in an airtight container for up to 1 week. Rewarm gently before using.