Preheat oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.
Place a steamer insert into a saucepan and fill with water to just below the bottom of the steamer. Bring water to a boil. Add cauliflower, cover, and steam until tender, about 3 minutes. Drain and cool until easily handled.
Chop cauliflower finely until it is the size of rice grains.
Measure out 2 cups cauliflower “rice” into a large bowl. Add bread crumbs, Parmesan cheese, egg, egg white, parsley flakes, minced onion, salt, and black pepper. Form into 30 small logs. Arrange on the lined baking sheet; spray with cooking spray.
Bake in the preheated oven until lightly browned on the bottom, 8 to 9 minutes. Remove from oven, flip, and spray with cooking spray. Continue baking until lightly browned on the other side, 8 to 9 minutes more.