In a medium bowl, whisk together the flour, baking powder, cinnamon and salt. Set aside.
In a separate bowl, combine the lemon juice and apples. Set aside.
In you mixer's bowl and using the paddle attachment, mix together the sugar and eggs on medium speed until fully combined. Reduce the speed to low and add part of the flour mixture. Allow to start combining, and then add the rest of the flour mixture. Mix until just combined.
Pour in the milk and mix until incorporated.
Fold in the apples.
Fill a frying pan halfway with oil. Heat over medium heat until the oil reaches 375 °F using a candy thermometer.
Drop 1/4 cup of batter into the oil and let fry until golden brown. Flip and fry the opposite side until golden brown. Insert a small knife into the center and see if it comes out clean. If not, allow to fry a little longer.
Transfer fritters to a cooling rack lined with paper towels and allow to cool.
Make the glaze by combining the sugar, vanilla, and 3 tsp water. Add water 1 tsp at a time until the glaze is a pourable consistency. Drizzle over the fritters after they have cooled.