Whole Foods has multiple locations in LA. That could be a start.

in my area, the brand is "Nonesuch" which I think is just fun. I usually find it on the top or bottom shelf in the supermarket's bakery aisle - look near the canned pumpkin and other pie fillings. I've bought it in both the jars and boxes - it's good in either form.

I just saw jars and jars of it at Ralph's!!