If you're bringing a camp stove with you, I highly recommend lentils and rice for dinners. They're non-perishable and very light when dry, take just 20min to cook, and they're easy to find (and cheap) in grocery stores or even convenience stores. You're sure to pass at least one tiny store every 2 days on your trip, so you don't actually need to carry that much on your bike at once. In addition, lentils and rice can be improved significantly by adding vegetables and salt, and I found that adding some high-quality canola oil made them taste significantly better, in addition to providing critical extra calories during a tour.
For breakfast, I usually had oatmeal of some sort. Like beans/lentils and rice, they are easy to find, non-perishable, lightweight, and cheap. They are similarly improved by adding things like dried fruit, trail mix, peanut butter, etc.
For daytime snacks, I am something of a Clif bar addict, so I tended to carry a bunch of those on my bike. These, or similar energy bars, are also easy to find these days in grocery and convenience stores basically nationwide. I also had a lot of trail mix of various sorts -- almonds, peanuts, walnuts, sesame seeds (surprisingly high in calories), whatever you come across. Stay away from chocolate in your mixes, though, because it melts quickly (unfortunately) when you're out in the heat. (Amusingly, though, I found that keeping chocolate in my northern panniers -- I was riding west so these were the ones on the right side of my bike -- kept it significantly cooler than the southern side.)
Also, depending on your budget, stop whenever you can to partake in the awesome diners that you're sure to come across ! I had a lot of fantastic home-made pie on my trip, which hands down beats granola bars and lentils and rice. :)