For decades with water I have taken a slightly rounded iced teaspoon of soy lecithin powder late afternoons or before bed for sleep. I also add a 1200 mg liquid soy lecithin softgel just for variety, although it is not necessary for results.
Lecithin has lots of phosphatidylcholine which relaxes the nervous system.
Eating chocolate can for two nights keeps me from getting back to sleep in the night, but chocolate flavonols are good for the brain.
I buy lecithin powder by the pound at BulkFoods, but they have been out of stock for months. Nuts.com has it, though.