Crossword puzzle clue "pudding's top layer if it's been left out"

Pudding's top layer, if it's been left out

Pudding layer

Wrap right over left, tuck right underneath, pull, pinch right in a loop, wrap left around, push left through hole to create loop, pull loops

Apple pudding left in the sun too long?

Like Play-Doh that's been left out of the container

Like day-old bread that's been left out

Ingredient that's been left out?

Layer-cake layer