So creamy? Bananas and maple! (8)
I believe the answer is:
sycamore
'maple' is the definition.
(I know that Sycamore is a type of maple)
'so creamy? bananas' is the wordplay.
'bananas' indicates anagramming the letters (informal term for mad).
'so'+'creamy'='socreamy'
'socreamy' with letters rearranged gives 'SYCAMORE'.
'and' is the link.
(Other definitions for sycamore that I've seen before include "Tree of maple family" , "Species of maple" , "Tree - so creamy (anag)" , "Tree producing propeller-shaped seeds" , "Mr O'Casey is in the tree" .)