Melt the fat. Wash parsley, shake dry and chop the leaves of 4 stems finely. Peel onion and chop finely. Drain the corn in a sieve. Mix both types of flour, baking powder, sugar, chilli, pepper and salt in a bowl.
Add buttermilk, eggs and butter and mix to a smooth dough. Leave the bacon out slightly in a pan. Add onion cubes and corn. Stir bacon, onions and corn into the dough. Pour the dough into a greased and flour-spread springform pan (24 cm Ø).
Decorate the surface with the remaining parsley leaves. Bake the cake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 20-30 minutes.