i don't think it's possible to maintain a spark per-se when raising kids because it's monotonous by default. if you've been with someone a decade, you're not going to elicit a wild spark, it shifts to a different thing.

i think probably the most realistic thing is to do something like a date night (maybe a spontaneous one) and just have time doing simple things, without the kids. send them to grandma, then go get a coffee etc. then you can just interact as people, not parents.

keeping it simple. now, if you were rich af, then it might be easier because you could just spend your time doing fulfilling things and doing all kinds of experiences, without the grind of work and worrying about bills etc