If it's about the money, consider this.

Software devs almost never get raises commensurate with what they can get by changing employers.

You make a good point. I'm relatively new to the industry (3.5 years) and this is job #2. I grew up poor, so I'm still in awe when I see how much I make – I guess I just don't know the etiquette here. It seems, according to the signal I'm getting from new offers, that I'm worth 25-35% more than I'm being compensated for. Particularly, it's interesting to see these new numbers without having volunteered my salary info. It seems like there is a ton of risk to asking for a raise based on other offers (admitting I'm interviewing elsewhere would probably scare my current employer), but also my current company is well-funded and I don't think it would impose a burden on them. I'm in a unique enough of a position to feel relatively safe right now (it's definitely sort of hard to hire right now). Any ideas?

If you have gotten better offers why are you still there?

The offers are relatively new FWIW. I'm in the midst of a project at the moment, which is the company's premiere project (greenfielding a core system). I'd kind of feel bad ditching mid-project.