Grease a high ring cake tin (approx. 1.7 l capacity; approx. 12 cm high, 13.5 cm Ø) and sprinkle with breadcrumbs. Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer).
For the dough, peel, wash and finely grate the carrots. Peel, quarter, core and grate the apple. Immediately sprinkle with lemon juice and mix with carrots. Mix 175 g butter, sugar, 1 pinch of salt and cinnamon with the whisk of the mixer for about 5 minutes until creamy.
Stir in the eggs one by one. Mix flour, starch and baking powder. Stir in briefly. Fold in carrots and apple.
Put the dough into the mould and smooth it down. Bake in a hot oven for 45-55 minutes, covering with aluminium foil after approx. 35 minutes if necessary. Take out and let cool down for about 10 minutes. Carefully turn out of the tin and let it cool down.
For the Frosting cream cheese, 25 g butter and icing sugar with the whisk of the mixer for about 5 minutes until smooth. Stir in the milk bit by bit. Spread Frosting on the cake. Chill for at least 30 minutes.