Here's the ingredient list for Toro Brownies, translated by me.
Sugar, wheat flour, reduced-fat cocoa, baking powder(calcium phosphate, sodium carbonate), coffee, salt, vanillin
I'm not sure about the fat reduced cocoa, for all I know that might just be what I think of as normal cocoa powder, and the rest are just regular ingredients anyone would use. No fancy surfactants and powdered fats etc.
I buy one bag that's dirt cheap and has everything I need including instructions. And it just has the same stuff I would be using anyway so there's no downside. No scary ingredients. Just freshly baked goods on demand.
First of all, properly stored flour, sugar, and cocoa powder doesn't attract bugs. Glass jars that seal well, done. Hell even plastic tubs. It expires pretty rarely as well, surely you can just bang out a couple of loaves of bread before that happens?
Anyway, yeah, is it not like, a very normal thing to keep flour, sugar, baking soda, cocoa powder, salt, perhaps yeast on hand? Butter, oil, some pasta, maybe some rice? Like, how do you cook otherwise, just buy small batches of these things every time?
Also the powdered fats lack the flavor that wet ones do.