What's sparkling, daddy? (3)
I believe the answer is:
pop
I believe this clue is a double definition.
'what's sparkling' is the first definition.
(sparkling drink)
'daddy?' is the second definition.
(I know that father can be written as pop)
(Other definitions for pop that I've seen before include "Cartoon sailor (showing amazement?)" , "Old jingle - . . . goes the weasel" , "Explode; Eton society" , "Burst - fizzy drink - modern music - US dad" , "Thus goes the weasel in children's rhyme" .)