Find a group of engineering leaders. (I'm a member of CTOLunches.com and the Rands Engineering Slack, but there are many others.) Learn from them. I bet there's one for financial systems engineers.

Take steps internally to become more technical. This may include stepping back from some of the other roles, promulgating hack weeks, or even shifting departments. Explain to the owners that you want to be more technical.

You can also hire a career coach who can give you some other steps.

Interview. Prepping and having an interview will teach you more about how "fit" you are for a senior engineer than any other advice.

Be prepared to take some kind of financial hit. Start saving and cutting back now (if you can). This will make the transition easier.

I feel you, I've been in a similar place. You can leave.