My granola bars use sweetened condensed milk and stay together really well and it makes for a dense crunchy/chewy granola bar.
Other binders I’ve heard of:
- Applesauce (didn’t work by itself very well)
- Applesauce with egg
- Peanut butter (or any nut butter)
- Heating honey and adding peanut butter
- 1 cup of dates soaked in 1/2 cup of water overnight and then blended to a paste (or instead of soaking overnight, use boiling water and let it soak till the water’s at room temperature).
- Egg, peanut butter, and maple syrup
The internet didn’t always answer binder questions with binder answers, so some of the sweeter ones may just work as sweeteners and not sweetener+binder. Hope this helps.
And here’s another granola bar recipe that sounds good. http://www.myhumblekitchen.com/2012/11/how-to-make-your-own-better-than-store-bought-chewy-granola-bars-in-any-flavor/