Lots of pasta, with no topping (6)
I believe the answer is:
oodles
'lots of' is the definition.
(informal term for a large amount)
'pasta with no topping' is the wordplay.
'pasta' becomes 'noodles' (noodles are a type of pasta).
'with no topping' means to remove the first letter.
'noodles' with its initial letter taken off is 'OODLES'.
(Other definitions for oodles that I've seen before include "a feast" , "masses" , "Lashings, loads" , "A lot" , "Very many, lots" .)