Keep 1 cup of lukewarm milk aside. Heat the remaining quantity of milk in a thick-bottomed pan. Keep stirring till it is reduced to half the quantity.
Mix some lukewarm milk with milk powder, stir and blend so that no lumps form. Also, make a paste of rice flour in some lukewarm milk.
Now, add the riceflour and milk powder pastes to the reduced milk.
Add in the coconut powder and cardamom powder, and the sugar. Stir gently till the sugar blends well into the milk and the mixture begins to thicken. Once the mixture begins to thicken turn off stove, add soaked blueberries and stir gently.
Allow to cool. Pour in small quantities into the kulfi moulds.
Screw the lids onto the moulds and freeze till set. Unmould and serve.