Cake decoration made from infused cream is no good at first (5)
I believe the answer is:
icing
'cake decoration' is the definition.
(I've seen this before)
'infused cream is no good at first' is the wordplay.
'at first' suggests taking the first letters.
The first letters of 'infused cream is no good' is 'ICING'.
'made from' is the link.
(Other definitions for icing that I've seen before include "East European nation" , "Cake-topper" , "Cake covering" , "Formation of frost on aircraft" , "Maybe Madeira's topping" .)