When I finally got bees and beehives in my survival world I had some string is my chest so I made a candle, and I also made some cake, but when I placed it on the cake it didn't disappear from my hotbar, it instead just put one on the cake but there was still the candle on my hotbar, and when I ate a slice the candle came of and then I had 2 candles. 

(and then when I finished typing that i made a video and I found I could have infinite candles from one cake!)

in the Minecraft snapshot 20w49a

the video said it exceeded the max amount of storage so I'm going to put in a URL download.

if you don't trust the download then don't click it.

[^Minecraft 20w49a - Singleplayer 2020-12-14 16-33-25.mp4]