I tried making rice cakes but honestly found it a faff, and not worth it when they have limited life even in the fridge. Also, very easy to get the consistency wrong and have them either fall apart or be impossible to swallow.
I might make a batch if I had a big multi-hour event. Otherwise, I stick to my diet of Soreen, bananas, Nutrigrain breakfast bakes, Eat Natural Bars, and homemade flapjack (easy and lasts forever in a tupperware box)…
Cycling Flapjack recipe (makes 12)
Ingredients optimised for on-the-bike digestion - substitute with what you have in the cupboard, but these work for me.
150g coconut oil
170ml sweet sticky syrup - date syrup is great, maple syrup, golden syrup, and honey ok too
100g soft brown sugar
Put these into a pan and let them gently melt / dissolve / come to the boil. Then stir in…
100g raisins / sultanas
A few chopped medjool dates, or perhaps some chopped up stem ginger*
200g oats (at least; add more oats if necessary until the mixture is quite stiff)
Other ingredients like seeds or nuts (but only if you know you won’t be riding too hard as these will be harder to digest)
Pour the mixture into a tin lined with greaseproof paper and bake (depending on thickness) for 20-25 minutes at 180 / 160 fan.
*I made a batch recently where I used stem ginger, and instead of date syrup, used the syrup from the ginger jar. My god they were good.