Preheat the waffle iron according to its instructions. Put the oats, cottage cheese, eggs, whey concentrate, milk, baking powder and vanilla in a blender. Blend until smooth, scraping down the sides as needed.

Let the batter rest for 5 minutes so the oats hydrate. It should pour in a thick ribbon. If it is too stiff to pour, blend in additional milk 1 tablespoon at a time; avoid making the batter thin.

Brush the hot waffle plates lightly with some of the measured oil. Add the amount of batter recommended for your iron, leaving room for expansion. Close and cook until golden, released easily and set through, usually 4–6 minutes. Egg-containing dishes should reach 160°F (71°C) in the center; check with a food thermometer.

Transfer the waffle to a wire rack. Repeat with the remaining batter, lightly greasing the plates as needed. Expect about four medium waffles, depending on the iron; divide the finished batch into two equal servings.

Serve promptly with optional toppings, counted separately. Let leftovers cool briefly on the rack, then refrigerate promptly in a covered container. Reheat until thoroughly hot in a toaster or oven, watching closely to avoid burning.