How to make a sheet cake 1/2 whote, 1/2 choco

Just a couple of ideas to try :)
the most common is to just pour both batters in at the same time. Batter is thick. It won’t really mix. It may just barely where it comes together.
Insert a piece of folded heavy duty foil where the line should be. Pour in both batters. Remove the foil for minimal mixing and bake.
Buy a special pan divider made just for this (come on though, I’d rather spend my money on other fun things)