Heat a heavy cast iron skillet/non-stick pan over medium-low heat, or heat an electric griddle to 350 degrees Fahrenheit. Lightly oil the surface of your pan with coconut oil, butter or cooking spray. If you're using a non-stick electric griddle like mine, you might not need any oil at all.
Place all the ingredients except for the grated apple in your blender. Blend until the batter is completely smooth (as in, you shouldn't see any remaining bits of oats or hear oats hitting the blades), pausing to scrape down the sides as necessary. Stir in the grated apple but do NOT blend again.