Note covered in pieces of rice cake (6)
I believe the answer is:
eclair
'cake' is the definition.
(I've seen this before)
'note covered in pieces of rice' is the wordplay.
'note' becomes 'la' (I've seen this in other clues**).
'covered in' means one lot of letters goes inside another.
'pieces of' indicates an anagram (I've seen this in other clues).
'rice' anagrammed gives 'ecir'.
'la' going into 'ecir' is 'ECLAIR'.
(Other definitions for eclair that I've seen before include "Oblong cream puff" , "Lacier (anag.)" , "Finger-shaped cream-filled cake of choux pastry" , "Finger-shaped, chocolate-iced, cream-filled cake" , "Long thin cake with chocolate and cream" .)