Sweet provided by charmer in guesthouse? (8)
I believe the answer is:
meringue
'sweet' is the definition.
(type of dessert or sweet)
'provided by charmer in guesthouse?' is the wordplay.
'provided by' says the answer is hidden in the clue (the answer is provided within the clue).
'MERINGUE' is hidden in the letters of 'charmer in guesthouse'.
(Other definitions for meringue that I've seen before include "a really sweet item" , "Dessert of beaten egg-white and sugar, baked crisp" , "Concoction of sugar and egg white" , "Confection based on egg whites" , "Crisp baked mixture of beaten egg whites and sugar" .)