I am a 18 year old girl who has a ex-bf that is 15. We really like each other a lot and we want to date. I'm trying to find a way around the law so we can date. Is there a way I can do that?

Nope, the law is pretty clear.
A friend of mine was 17, his girlfriend was 15.
She got pregnant (condom burst). Her parents had him charged with statutory rape and registered as a paedophile. It destroyed his life.
That's the absolute extreme and it's veeeeeery rare, but it can happen.

The two of you could have a happy consenting relationship, but all it takes is one random person to object and the law has to get involved.
Some things are worth waiting for.

Where do you live, laws vary from state to state

There are no laws about dating, you are free to date ( but I have no idea what a 18 year old girl could have in common with a 15 year old boy.

But if they want to have sex, that is illegal in most places, but it will vary by location