Heat the milk to lukewarm (approx. 35 °C). Pour into a bowl and add the yeast. Leave to stand for 5 minutes. Melt the butter and leave to cool to room temperature. Sieve the flour with the salt and cinnamon over a large mixing bowl. Add the egg. Pour in the yeast mixture beating all the time at a low setting to create a smooth batter. Leave covered for a minimum of 1 hour in a warm, draught free place.
Cut the mango into two halves along the stone. Score each half into squares without cutting through the skin. Turn out the halves with your thumb and slice off the cubes. Or use a mango slicer. Mix the mango cubes carefully through the batter.
Heat the sunflower oil in a pan to 175 °C or use a deep frier. Use an ice cream scoop to scoop balls out of the batter. Drop each ball carefully into the oil. Dip the ice cream briefly into the oil to prevent the batter from sticking. Bake around 4-5 doughnuts in approx. 5 minutes until golden brown. Remove from the oil and drain on kitchen paper. Serve sprinkled with icing sugar.
Tip: Heat the doughnuts in a pre-heated oven at 175 °C for 5-10 minutes the next day
