No, because everyone who has Mint Cakes, is dropping them to buy Staff of Light's and the Hex + Focus to make them rare. Haven't you noticed? Bandos, Dragon Claw, GS's, and everything is dropped while Staff of Lights, Hex, and Focus' are rising...
The minigame updated. Not only is it easier to get it as a reward, you can get up to 11(?) at a time. Thus, there's way more in the game, which means extremely less demand for them, so they drop..
Along with gnome seed pods, the reward percentage increased and you can get up to 10 mints per reward. They are almost junk at the moment, as 100% run energy is not worth 25-30k.