In a large mixing bowl, whisk together all-purpose flour, baking powder, ground cinnamon, ground nutmeg, salt, and granulated sugar.

In a separate bowl, combine the beaten egg, milk, melted unsalted butter, and vanilla extract. Whisk until smooth.

Pour the wet ingredients into the dry mixture and gently fold using a spatula until just combined.

Dice the medium apple and fold it into the batter.

Allow the batter to rest for about 5-10 minutes.

Preheat a lightly oiled griddle or non-stick frying pan over medium heat.

Using a measuring cup, pour ¼ cup of pancake batter onto the griddle for each pancake.

Cook the pancakes for about 2-3 minutes until bubbles form on the surface.

Gently flip the pancakes and cook for another 2-3 minutes until golden brown.

Place cooked pancakes in a preheated oven at 200°F to keep warm if necessary.