The masked attackers grabbed the female worker, who is in her 50s, from behind and threatened her with a knife as she opened the shutters of the Co-op store in Corslet Place in Currie yesterday at 5.40am.
Forcing her inside, they made the terrified worker unlock the safe before seizing a four-figure sum of cash.
The robbers then made the woman hand over the keys to her own blue Nissan Almera, before making their escape in the vehicle. Police said the worker was not harmed, but was extremely distressed. The stolen vehicle has since been recovered and forensics officers are understood to be examining it. It is said to be intact and has not been burnt out or seriously damaged.
Detectives have also already obtained CCTV from inside the store and the surrounding area.
The footage shows the robbers waiting nearby from 5.15am before striking around 25 minutes later. Detective Constable Richard Emerson, of Corstorphine Police Station, said: "Already from CCTV we have seen that they have been in and around the area for a good half an hour, so we'd be keen to hear from anyone who was around the Corslet Place area between 5.15am and 5.45am."
The shop is in a quiet, secluded area where local residents prominently display their Neighbourhood Watch signs.
Police asked anyone who lives in the area to contact them if they saw the robbery, but most said they had not been awake, and had only learned of the raid when they saw police cars swooping.
One resident said the shop had been targeted before, though never in an armed raid.
The first suspect is described as white, 5ft 7ins, of medium build, and was wearing grey Adidas trainers with three stripes, dark blue or black jeans, green and black checked shirt, and black leather gloves.
The second man was also white, 5ft 4ins tall, of thin build, and was wearing black trainers, grey jogging bottoms with a stripe running down each leg, a black zip-up top, and black gloves. Both men were wearing balaclavas.
A spokesman for The Co-operative in Scotland said: "The member of staff was unhurt, but badly shaken. CCTV footage has been given to the police."
Anyone with any information should contact police on 0131-311 3131, or Crimestoppers on 0800 555 111.