I recently posted something about cat spasms as well. In my cat's case it's different though however I think one of the advices given to me would be good for you too and that is to try to catch it on video so your vet can see it.
I know it's hard but if you could that would help.
Blood work could help a lot too to discard a number of things. (including seizures)
Best of luck and good vibes
for you and Malia she sounds like a wonderful little lady.
P.S. bingocake's kitty sounds so cute and awesome.