I have tried something which had worked pretty well with mine: asking them "what do you want to do for your birthday?" instead of "what do you want to have?".

In the end, the underlying question is the same, something like : " what do you want to experiment/live/feel in that special moment? I am making myself totally available to you for that, as far as it is possible"

And what will they really remember and enjoy ? The feeling, the joy... It can be brought the physical present they want so much, but the present itself is often very quickly put aside, a matter of weeks or even days sometimes ! But the feeling might stick as a lifelong memory.

I liked to use the word "present" here 😊