marshmallowy

adjective4

1. •
   Resembling or characteristic of a marshmallow.

   • An ice-cube crusher for $1, a cake slicer, something like a miniature rake, to cut smoothly through the marshmallowiest frosting without a leak, for $1, […] were just a few I put on my list. — 1933
2. •
   Soft and fluffy.
3. •
   Tending to be a pushover; overly accommodating.

   • “It changed Gable from a heavy to a comedian in It Happened One Night. It changed Jean Arthur from a marshmallowy ingenue to a hard-boiled wise- cracker in The Whole Town's Talking.” — 2002
4. •
   Vacuous.