You can call someone a muffin meaning:
That they’re an adorable, smol, and cute muffin head. (You’re a muffin by this definition since I know you’re adorable)
NOW STOP DENYING THAT YOU’RE A MUFFIN AND ACCEPT THAT YOU’RE ADORABLE-
“You’re a muffin”
“No you areeeeee”
“You’re the best muffin”
“How dare”
There is no explanation for this one. It is what it is
Muffin has arrived