Biscuit pack trimmed in dark red (8)
I believe the answer is:
macaroon
'biscuit' is the definition.
(I know that Macaroon is a type of biscuit)
'pack trimmed in dark red' is the wordplay.
'trimmed' means to look at the middle letters (the external letters are trimmed from the word).
'in' is an insertion indicator.
'dark red' becomes 'maroon' (I've seen this in another clue).
The middle letters of 'pack' are 'ac'.
'ac' going within 'maroon' is 'MACAROON'.
(Other definitions for macaroon that I've seen before include "Type of biscuit" , "Sweet almond biscuit" , "Sweet bit of food" , "Almond or coconut biscuit" , "Something nutty to enjoy" .)