Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper.
In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, cinnamon, and salt.
In a medium bowl, whisk the eggs, milk, melted butter, and vanilla extract until well combined.
Add the wet ingredients to the dry ingredients and stir until just combined.
Gently fold the diced apples into the batter.
Drop 1/4 cup portions of the batter onto the baking sheet, spacing them 2 inches apart.
Bake for 12 to 15 minutes or until the fritters are golden brown and a toothpick comes out clean.
Prepare the glaze by whisking the powdered sugar, 2 tablespoons of milk, and 1/2 teaspoon of vanilla extract in a small bowl until smooth.
Transfer the fritters to a wire rack and drizzle the glaze over them while still warm.
Allow the glaze to set for 5 minutes before serving.