Isles: Look at this! What is that white substance?
Rizzoli: Fluff.
Isles: Light, downy particles of cotton?
Rizzoli: It's marshmallow, and the brown substance is called peanut butter. It's ground up, heavy, oily particles of peanuts. What, they didn't have that in your fancy boarding school.

i am a major rizzoli and isles fan!!