In a large mixing bowl, whisk together flour, baking powder, cinnamon, nutmeg, salt, and sugar until there are no clumps.

In a separate bowl, whisk together egg, milk, melted butter, and vanilla until smooth.

Carefully pour the wet ingredients into the dry mixture, folding gently until just combined.

Fold in the diced apple until evenly distributed.

Let the batter sit for about 5 to 10 minutes.

Heat a lightly oiled griddle or frying pan over medium heat, around 350°F.

Using approximately ¼ cup of batter for each pancake, pour it onto the hot cooking surface.

Cook for about 2 to 3 minutes, or until bubbles form and edges look set.

Flip each pancake and cook for an additional 2 to 3 minutes until golden brown.

If cooking in batches, place finished pancakes in a preheated oven set to 200°F to keep warm.