In a mixing bowl, combine the cottage cheese and yogurt until smooth.
Add the egg, baking powder, lemon zest, and lemon juice. Mix well.
Fold in the oats until just combined. Add more if the mixture is too wet.
Preheat the oven to 180°C (350°F) or prepare your air fryer.
Spoon the mixture into 6 silicone muffin cups. Place them on a tray (for oven) or directly in the air fryer basket.
Air fryer method: Set to Bake and cook for about 15-20 minutes, until golden.
Oven method: Bake on the middle rack for about 25 minutes, until golden and firm to the touch.
Transfer the muffins to a wire rack to cool, then serve warm or at room temperature.