Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper or a silicone mat and, if using parchment, lightly spray it with oil to prevent sticking.
In a medium bowl, whisk together the oat flour, baking powder, and kosher salt until evenly combined.
Add the drained cottage cheese and beaten egg white to the dry ingredients and mix with a fork or spatula until the mixture forms small crumbles.
Knead the mixture in the bowl by turning and folding it about 20 times, until it becomes smooth and pliable, with a play-dough–like texture.
Divide the dough into 4 equal pieces and shape each into a ball. Flatten each ball into a round and place them on the prepared baking sheet.
Brush the tops with a little beaten egg or egg white for an egg wash, then sprinkle with everything bagel seasoning or sesame seeds if using.
Bake on the top oven rack for 22 to 25 minutes, until the rolls are golden and set. Remove from the oven and let cool at least 15 minutes before slicing.
Optional air-fryer method: preheat the air fryer to 280°F (140°C). Work in batches without overcrowding and air-fry for 15 to 16 minutes, or until golden; no need to turn. Let cool at least 15 minutes before cutting.
