Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper.

In a mixing bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and sugar.

In another bowl, beat the egg, then add the milk and vanilla extract. Mix well.

Combine the wet ingredients with the dry ingredients and stir until just combined. Fold in the diced apples.

Drop spoonfuls of the batter onto the prepared baking sheet, leaving space between each fritter.

Bake in the preheated oven for 20-25 minutes, or until golden brown.

In a small bowl, mix together the powdered sugar, milk, and vanilla extract until smooth.

Drizzle the glaze over the warm fritters before serving.