Preheat the waffle iron. Heat it to medium or medium-high. Lightly grease with oil or nonstick spray.
Blend the wet base. In a blender, add cottage cheese, eggs, milk, vanilla, and oil.
Blend until completely smooth.
Add the dry ingredients. Add oats (or oat flour), protein powder, baking powder, salt, and sweetener. Blend again until just smooth. The batter should be pourable but not runny.
If too thick, add a splash of milk; if too thin, blend in a tablespoon more oats.
Rest briefly. Let the batter sit 3–5 minutes so the oats hydrate and baking powder activates. This helps with lift and crisp edges.
Cook the waffles. Pour batter into the hot iron, covering the grates without overflowing. Close and cook until deeply golden and crisp, usually 3–5 minutes depending on your iron.
Hold for crispness. Place finished waffles on a wire rack instead of stacking to keep steam from softening them.
Serve. Top with berries and a dollop of Greek yogurt, or go savory with a fried egg and hot sauce.