In the episode “Rory's Birthday Parties.”
LORELAI: What’s that?
EMILY: It’s dessert.
LORELAI: It’s pudding.
EMILY: Well if you knew what it was why did you ask?
LORELAI: You don’t like pudding.
EMILY: Yes, but you like pudding.
LORELAI: Oh, I love pudding. I worship it. I have a bowl up on the mantel at home with the Virgin Mary, a glass of wine, and a dollar bill next to it.
RORY: I’ve never had pudding from a crystal bowl before.
EMILY You like the bowl?
RORY: Mmm.
EMILY: Put a post-it on it when you’re done.
Taken aback by a bowl of pudding, Lorelai exclaims this in shock. Apparently, Emily has never served pudding before because she thinks it is a hillbilly dish and believes it is below her.
(The “post-it” was in reference to an earlier request by Emily to put post-it’s on anything the girls would like to inherit after Emily and Richard die.)