Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper and lightly coat it with cooking spray.
In a mixing bowl, whisk together the flour, baking powder, cinnamon, salt, and sugar until well combined.
In another bowl, mix the egg, milk, applesauce, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and mix until just combined. Be careful not to overmix.
Gently fold in the diced apples until evenly distributed in the batter.
Using a spoon or your hands, drop heaping tablespoons of the batter onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 20 minutes, or until the fritters are golden brown and a toothpick inserted in the center comes out clean.
Remove from the oven and let them cool for a few minutes before serving.