Refreshment that is ace, including bananas etc (3,3)
I believe the answer is:
ice tea
'refreshment' is the definition.
(refreshing drink)
'that is ace including bananas etc' is the wordplay.
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'ace' becomes 'a' (abbreviation).
'including' is an insertion indicator.
'bananas' is an anagram indicator (informal term for mad).
'ie'+'a'='iea'
'etc' with letters rearranged gives 'cet'.
'iea' going around 'cet' is 'ICE TEA'.
(Other definitions for ice tea that I've seen before include "Cool non-alcoholic drink" , "Cold summer drink" , "refreshing drink" , "Chilled drink flavoured with lemon" , "refresher" .)