Third of sugar's to sift on surface for baking (7)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
griddle
(Other definitions for griddle that I've seen before include "cooking utensil" , "Flat heated surface used for cooking" , "Iron plate for cooking on" , "Circular iron plate used for baking" , "Heated metal cooking surface" .)