Place the eggs, egg whites, cottage cheese, oat flour, and vanilla extract (if using) into a blender. Blend until the mixture is fully smooth and there are no lumps. Let the batter sit for about 5 minutes to allow air bubbles to settle and the flour to absorb moisture.
Warm an 8-inch nonstick skillet over medium heat. Lightly grease the surface with oil or cooking spray.
Pour about ¼ cup of batter into the center of the pan. Immediately tilt and rotate the skillet to spread the batter into a thin, even layer.
Cook for about 1 minute, or until the edges begin to lift and the bottom turns lightly golden. Flip carefully and cook the other side for another minute until set and flexible.
Repeat with the remaining batter. Stack the finished crepes on a plate and loosely cover with foil to keep them warm.
Serve right away with your preferred fillings or toppings. If not serving immediately, allow the crepes to cool fully before storing.