Heat the oven at 180°C and grease the baking pan with non-stick cooking spray. Put the grain into the baking pan and evenly spread it over the pan. Then layer with it with grated apples. Sprinkle with sugar, spices and salt. Pour over the kefir and milk. You can mix them together first or pour each one separately. Use just enough milk and kefir to cover the apples. Sprinkle with ground hazelnuts. Using a spoon, push down and dip the hazelnuts in milk. If necessary, add some more milk to cover the hazelnuts.
Bake at 180°C for about 45–60 minutes until gold in color. Let the baked porridge cool down, cut into squares and serve with crème fraîche (mixed with icing sugar). Dust with cinnamon or sugar.