Little bit of dessert Alex essentially leaves (5)
I believe the answer is:
crumb
'little bit' is the definition.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for crumb that I've seen before include "of the farmhouse?" , "Flake of bread" , "Morsel of bread" , "offering a little comfort" , "Tiny piece of bread or cake" .)