I see that you wrote this on Christmas and didn't get a reply so I figured I'd shoot.
There are a lot of different foods bettas like. I currently alter between tropical flakes, hikari pellets and freeze dried blood worms, with the blood worms being a snack 2 times a week. Hikari makes a set of different freeze dried foods that are vitamin enriched that you could probably alternate as a two time weekly snack. These are pricey but they last a long time and are always fresh and somewhat moist compared to other brands. They offer Daphnia, Krill, Blood Worms, Ocean Plankton, Tubifex Worms, and Brine Shrimp. I've tried the Blood Worms, Tubifex Worms and the Brine Shrimp and my 7 bettas love them.
This is what they look like
Hikari Freeze Dried Tubifex Worms at PETCO