Peel, core, and dice the apples up into very small chunks. Set aside covered with a damp piece of kitchen paper over them while you make the fritter batter.
In a large bowl, whisk flour, baking powder, and cinnamon.
In a seperate bowl, whisk the eggs, buttermilk, brown sugar, and vanilla extract.
Stir the wet into the dry ingredients until just combined, and then fold in the apples.
In a large saucepan over medium heat, pour oil to a 2-3 inch depth and set a thermometer in the oil to measure the temperature and set a wire rack on a baking tray and place near the saucepan.
When the oil has reached 350°F/180°C (medium heat), carefully drop a large dessert spoon of batter into the oil, roughly ¼ cup of batter.
After 2-3 minutes, when one side is golden brown then flip and let the other side cook until golden brown on the other side.
Lift the fritters out of the oil and place on the wire wrack.
Once all the fritters are cooked, dunk them in the glaze and let dry back on the wire rack.
These fritters are best the day they are made, but any leftovers can be stored in an airtight container in the refrigerator for up to one day.