I’ll usually start with a Denver rice cake or Red Lentil rice cake recipe, and riff on it. I tend not to eat meat, so I’ll swap the ham for black beans. Also I like to add vinegar-based hot sauces like Tobasco both for flavour, and for that pickle-juice anti-cramping effect. The Warm Dough two-bite pies are a nice option as well.
Nutritional info is included for all of the recipes, though all can be thought of as starting points for your own tastes which will change the numbers somewhat.
Sourcing the Reynolds wrap has been difficult sometimes up here, and it took a few tries to get the wrapping technique down for the rice cakes but we’re all good now!
Edit: not in the cookbook, but if I’m being lazy and doing a long trainer ride, I’ll sometimes just boil some potatoes, quarter them, salt liberally and keep them on a plate within reach. Really high glycemic index, salty/savoury and really easy to get down. Plus they’re dirt cheap.