In a large bowl, whisk together the dry ingredients: 1 1/2 cup all-purpose flour, 3 tablespoons sugar, 1 tablespoon baking powder, 1/2 teaspoon salt, and 2 teaspoons cinnamon.
In a separate bowl, whisk the wet ingredients: 1 cup milk, 2 large eggs, 1 teaspoon vanilla extract, and 2 tablespoons unsalted butter (melt the butter first and let it cool slightly).
Pour the wet mixture into the dry ingredients and stir gently with a whisk or spatula until just combined; the batter should be moistened but may still have small lumps.
Core and finely dice the 2 medium apples. If you want apple for topping, set aside some diced apple; otherwise fold all of the diced apples into the batter.
Heat a nonstick skillet or griddle over medium heat until hot. Pour portions of batter onto the skillet to form pancakes of your preferred size, leaving space between them.
Cook the pancakes until bubbles form on the surface and the edges look set, then flip and cook until the other side is golden brown. Repeat with the remaining batter, keeping finished pancakes warm if desired.
Serve the pancakes topped with any reserved diced apples and 4 tablespoons pure maple syrup.