Ok this depends a LOT on how many retards you have on your server, and how many people is on your server in general. Myself i have now made like 500g from this, spending around 20 minutes.
Go just outside silvermoon city and grind the fiery birds (don't remember name :P). They drop 1-2 eggs each, grind for a while.
Get the recipe for gingerbread cookies and make cookies of all eggs (You need som spices that you can buy from the winter goblin guys, but they costs close to nothing).
Sell them on the ah. On my server there is not very much players, and there is not any cookies on the ah (yet). I put them out for 29g in stacks of 5.
The cookies i putted on ah (like 100) got sold in less than two hours.
So some calculating:
Farming eggs, around 5 per minute.
One egg = One cookie = around 5g.
1 hour of farming = 1500g.
I state it once again; depends on how many players there is on your server. On my friends server they are 1g each. (Still pretty good money, like 200-300g/hour.)