Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Line the recesses of a muffin tray (for 12 pieces) with paper cups. Cream 125 g soft butter, 1 pinch of salt and sugar with the whisks of the mixer.
Stir in the eggs one by one. Mix flour, cocoa and baking powder. Alternate with the buttermilk and stir briefly into the butter-sugar cream. Stir in food paste and distribute the dough into the moulds.
Bake in a hot oven for 15-20 minutes. Remove from oven. Leave to rest briefly in the muffin tray, lift out and allow to cool.
For the topping, whisk 75 g soft butter and icing sugar with the whisks of the mixer for approx. 4 minutes until light creamy. Stir in cream cheese by the spoonful. Pour into a piping bag with a medium perforated spout.
Spray cream on the cakes. Decorate with chocolate code.