You don't want to be rude as you're the one who came barging into someone's home. So you take the pink cookie and devour it in a couple of bites. Your mouth waters at the wonderful taste of the cookie. Never have you had a cookie quite like that before.
The strange woman watches you like a hawk, making sure you eat the entire cookie. After you finish it, she just stands there watching you, like she's expecting something.
You start to feel a little nervous, you don't know what to do. "ummm... thank you for the cookie, but I think I better gooo....", you trail off as your voice starts to change pitch, it's getting higher!
The woman looks at you and shakes her head. "I'm afraid you're not going anywhere, just relax and let the cookie finish it's work."
You're not sure what she means, but you start to feel odd. You look down at yourself but don't see anything out of whack. Something brushes against the sides of your neck, you scratch at it and you hand brushes against hair. Your hair, you realize, and it's growing longer! You feel yourself begin to change more rapidly. You can feel yourself getting slimmer, more delicate. An odd sensation on your chest draws your attention to your newly developing breasts.
Soon, what once was a young man, a pretty young woman stands in a strange kitchen being watching by a strange woman.
Then...