Level 75-80 in 12 minutes (32m+ EXP/hr) WOTLK Classic

Utilizing 20% exp from heirlooms, 50% from Joyous Journeys, and repeatable quest items in Dalaran, players are able to level from as low as 70 up to the max of 80 in minutes. Exp rates upwards of 30 million per hour are possible with this method provided you have enough quest items.

Both Sealed Vial of Poison and Waterlogged Recipe work the same way. In this configuration each item is worth 37k experience, and rewards Kirin Tor rep and a small amount of gold as a bonus (and as many cooking tokens as you could ever need).