Quit if your side projects seems like a better future for you. While it's admirable that you feel for "a major California company", I can assure you that this

Quit if your side projects seems like a better future for you. While it's admirable that you feel for "a major California company", I can assure you that this company has no feelings for you. Just recently we've heard of major layoffs at Yahoo, IBM, Zenefits. Your company will have no regrets about firing you, mostly because a company is a legal fiction, not a person. I would also disregard the advice of talking to the company. There's a huge discrepancy of power between you and a company so they can make your life miserable (a lawsuit) even if you didn't do anything wrong or do what you think is good for the company. Also, the larger the company, the more risk averse they are, so forget negotiating some one-off deals with them (so that you can keep working for them at the same time as working on your project). You're probably over-estimating your importance to the company. They became "a major California company" before you ever joined and they'll remain such company after you leave. Quit and don't look back.