Pastries one prepared with French art in these? (11)
I believe the answer is:
patisseries
'these?' is the definition.
The definition suggests an adverb but the answer is not.
'pastries one prepared with french art' is the wordplay.
'one' becomes 'i' (Roman numeral).
'prepared' indicates anagramming the letters.
'with' says to put letters next to each other.
'french art' becomes 'es' ('is' in French - 'art' can mean 'is' eg 'thou art').
'pastries'+'i'='pastriesi'
'pastriesi' is an anagram of 'patisseri'.
'patisseri'+'es'='PATISSERIES'
'in' is the link.
(Another definition for patisseries that I've seen is " shops".)