In a medium bowl mix flour, baking powder, cinnamon, sugar and salt. In a separate bowl beat the egg and then add milk, whisking all together. Then whisk the egg and milk mixture into the flour mix until combined. The batter should be thick.
Slice the apples into 0,5 cm thick slices, then using a piping nozzle or small cookie cutter, cut the middle of each apple slice, discarding the core afterwards.
To a large heavy-bottomed pot add oil. When the oil is hot (it should be about 190C ), begin dipping each apple ring into the batter, shaking off any excess. Then carefully lower each ring into the oil. Fry only a couple of rings at a time until golden on each side. When done, transfer onto the paper towel. Repeat with the remaining apple rings.
Serve warm, dusted with powdered sugar. Enjoy!