One producing eggs in blanket? (5)
I believe the answer is:
layer
I believe this clue is a double definition.
'one producing eggs' is the first definition.
(I've seen this before)
'blanket?' is the second definition.
(blanket is a kind of layer)
'in' is the link.
(Other definitions for layer that I've seen before include "Blanket - single thickness" , "Seam" , "One of several thicknesses" , "Early (anag.)" , "Single thickness and hen" .)