In a medium bowl, combine the milk, yogurt, eggs, butter, and vanilla. Whisk these ingredients together until smooth.
Add the flour, sugar, baking powder, cinnamon, and salt to the bowl. Gently whisk until just combined.
Fold in the shredded apple or slice the apple thinly if you prefer.
Heat a nonstick or cast-iron skillet over medium heat. Add a small amount of butter to the pan, allowing it to melt and coat the surface.
Using a ladle or measuring cup, pour about ¼ cup of batter for each pancake onto the skillet. Spread it out gently.
Once you see bubbles and the edges look set, carefully flip the pancakes. Cook for an additional two to three minutes on the other side until golden brown.
Continue this process until all the batter is cooked.
Serve the pancakes warm, piled high, and topped with additional maple syrup.
