It's been years since I've seen the Congratulations screen for Lv46 so I can't say for certain what you saw so I've looked through my personal inventory of every recipe on offer - past and present, goal or standard, limited, removed or otherwise. Sadly, I do not see any recipe that unlocks at level 46 in the basic appliances.
The only thing that stands out to me for Lv 46 is that the Treasure Oven becomes available to purchase. Below is an image of the appliance and its recipes; perhaps one of them is what you saw?