Strange sweetheart's after cold pancakes (8)
I believe the answer is:
crumpets
'pancakes' is the definition.
(crumpets are pancake-like cakes)
'strange sweetheart's after cold' is the wordplay.
'strange' becomes 'rum' (synonyms).
'sweetheart's' becomes 'pet's' (both are terms of endearment).
'after' means one lot of letters go next to another.
'cold' becomes 'c' (eg on taps).
'rum'+'pets'='rumpets'
'rumpets' put after 'c' is 'CRUMPETS'.
(Other definitions for crumpets that I've seen before include "Spectrum (anag)" , "Teatime fare" , "Soft toasted and buttered cakes" .)