The pin on the map shows that the restaurant is in the Busan Station but it is not. We searched in the station for quite a while but could not find “exit 11”. Then we went to the Jungang subway station as it says but could not find it there either. We then went to the old address and found the old place where it said that they had moved to the Jungang station inside another café! When we finally got there it was closed!! It was 7 pm and the sign said they should be open until 8 pm.. So really not good experience for us! We really wanted to try their burgers.. Hope you guys have better luck finding it than me and my husband ;)

The pin is/was wrong, it is not located in Busan station. (I have sent in an update)
Go to Jungang station exit 11 just as it says in the address here.
There is however no sign that it is moomoos. It is a vegan bakery called KVIA. Nothing implies that it is moomoo except a menu taped to the cashiers desk.
Also the opening hours is eighter until 18.00 or 20.00. There are two signs so not sure which applies.