Teaching: Tradeoff between ease of grading, ease of cheating

It occurred to me that as I make homework assignments easier for myself to grade, I also make it easier for students to cheat on them.

At one end of the scale there's multiple-choice questions which are absolutely trivial to copy, and impossible for me to prove any shenanigans unless I use high-powered statistical software.

At the other end of the scale is an original essay, which is basically impossible to copy without it being obvious (I can even type key phrases into Google to check for copying from outside sources), but original works take at least half an hour to grade each... which adds up in a 30-person class.

I want to narrow the scope of the essays, perhaps even reducing them to bullet-point lists, next time I teach the class. But now I'm realizing that the more time I save on grading, the more time I have to put into making the assignment cheat-proof, so I'm not sure if I can actually save time at all.