Preheat oven to 350 degrees F (175 degrees C). Spray a baking sheet with cooking spray.
Whisk ground corn cereal, sorghum flour, potato starch, rice flour, sugar, cornstarch, xanthan gum, yeast, and salt together in a large bowl.
Whisk rice milk, canola oil, and vinegar together in a separate bowl. Beat rice milk mixture into corn cereal mixture with an electric mixer, adding rice flour or water as needed to form a smooth dough.
Divide dough into 10 equal pieces and form into 3/4-inch-thick rolls about 3 inches in diameter. Place rolls on the prepared baking sheet; brush lightly with olive oil. Cover rolls with a light cloth and let rise until doubled in volume, about 30 minutes.
Bake in preheated oven until tops are golden brown, about 25 minutes. Let cool on a wire rack.