Dessert for one adding up bill? (6,7)
I believe the answer is:
summer pudding
'bill?' is the definition.
Both the definition and answer are singular nouns.
Maybe there's a link between them I don't understand?
'dessert for one adding up' is the wordplay.
'dessert' becomes 'pudding' (pudding is a kind of dessert).
'for' says to put letters next to each other (I've seen this in other clues).
'one adding up' becomes 'summer' (someone doing sums).
'pudding' after 'summer' is 'SUMMER PUDDING'.
(Other definitions for summer pudding that I've seen before include "Dessert of pureed soft fruits with bread or sponge" , "Dish of soft seasonal fruits in bread" .)