Same thing happened to me but it was my chocolate pie for the garden fair and my giant pumpkin and I restarted my last save to see what happened and it did it again no pie or pumpkin, it’s not in the fridge, in sims inventory, or household it just completely vanished and it was a good pie. And big pumpkin.
Same thing happened to me with my oversized pumpkin! Harvested it right before the fair, checked to make sure it was in my sim's inventory before I left, then traveled to the fair using the button on the flyer and when I got there it disappeared. And had the cow version happen to her dad a generation ago too.
