The frightening robbery happened 9.20pm on Saturday, when the victim was in her silver Volkswagen Polo GTI outside Shezzaan's Restaurant in Halifax Road.
Two masked men approached the car - which was carrying the woman's 11-month-old baby - and demanded she get out.
Police said one of them men was carrying a metal object, but neither the woman or baby were injured.
They stole the car and drove off in the direction of Odsal Top.
One of the suspects was believed to be wearing a hooded top with a grey body, back and hood and darker grey or black sleeves.
Detective Constable Simon Turton, of Bradford District CID, said: "This was understandably a frightening experience for the victim and her child. We treat any use of a weapon extremely seriously and it is vital that we identify and bring to justice those involved.
"Our enquiries are continuing and we would urge anyone who was in the Halifax Road area at the time, or anyone who may have seen the vehicle shortly afterwards to call Bradford District CID via 101, quoting crime reference 13160707596."
Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.