If you have honey in a cooking pot and a stack of bowls in your hand, you can right click the honey into the stack of bowls. You can then separate the bowls and it will duplicate the amount of honey in each bowl. So for example I have 3 bowls stacked and I fill it to 1 liter then I have 3 bowls of 1 liter.
Separate issue, but it is super unclear how to make jam in the game. It just says cook units of honey with berries, but I tried so many different combinations and none of them worked. I did some googling and couldn't find any recent info or pictures about making jam. I discovered the honey duping bug while trying to make jam.