Clean, wash and finely grate the carrots. Separate eggs. Beat egg whites, salt and 2 tablespoons of water until very stiff. Add sugar while stirring. Stir in amaretto and egg yolk briefly. Mix almonds, flour, baking powder and carrot grater and fold into the egg mixture.
Line the bottom of a springform pan (24 cm Ø) with baking paper. Pour in the dough and bake in a preheated oven (electric: 175 °C/ gas: level 2) for 40-45 minutes. Let it cool down on a cake rack.
Remove the base from the mould and cut through 1 x. Spread 2/3 of the jam on the bottom base and place the top base on top. Chop the pistachios, except for a few. Spread the rest of the marmalade on the edge of the cake and sprinkle with 2/3 of the chopped pistachios.
Mix 200 g icing sugar and orange juice to a smooth glaze. Spread the icing on the surface of the cake. Knead marzipan and remaining icing sugar and colour orange with food colouring.
Form small carrots and carrot heads from the mixture. Nick them slightly with the back of a knife. Cut the remaining whole pistachios in half and put them into the carrots as green. Decorate the cake with carrots and sprinkle with the remaining chopped pistachios.