A moist, chocolatey cake, perfect for a large gathering, with rich flavor and a light texture.
Place butter and chocolate together in a pot, melt over low heat, stirring occasionally until smooth. Remove from heat and let cool slightly.
Place the six egg yolks in a bowl, add the sugar and whisk until light and creamy.
Sift flour and baking powder together and add to the yolk‑sugar mixture. Gently fold in with a spatula.
Slowly pour the slightly cooled chocolate‑butter mixture into the batter and stir evenly until a homogeneous batter forms.
Pour the batter into a greased cake pan, bake in a preheated oven at 180 °C for about 30–35 minutes, until a toothpick comes out clean. Remove the cake from the oven, let it cool in the pan briefly, then release from the pan and cool completely on a cooling rack.