Hello njwilde,
Robo's are not diabetes prone so you can feed a little corn & pea flakes. But I would not recomend the sugary hamster treats found in pet shops.
For treats that are good I feed some of these:
Nuts! only a small amount each day because they are fatty
Dari Nibble Cob - Naturals Range this is a big spike of Dari so break some off & give it to the ham to pick off while you hold it or put in cage.
Millet spray they are big so break some off & hold it while hammy pulls off the millet
Mix some Puffs up, Puffed Rice, Millet & Buckwheat (make sure the ingredients is 100% & no added anything can be found in health food shops)
Saflower seeds
Rice cake (with no salt again may need to visit a health food shop)
Broccoli
French bean
Runner bean
Sprout
Cabbage
Clover cookies Naturals range
Shrimp cookies Naturals range
Also a little cooked pasta
Cooked Chicken
Cooked egg
Also a good hamster mix for every day food. If you wanted to buy mine you could feed any of the three mix's as Robo's are not diabetes prone. Here's the link
Dwarf Hamster - Basic - £1.92 : ratRations.com
Or people feed Burgess Dwarf hamster harvest, Burgess hamster harvest, or Harry Hamster.