Preheat oven to 350°F (180°C). Grease and dust a 9-inch (22 cm) cake pan with cocoa powder.
In a large bowl, beat the eggs with the sugar and vanilla sugar until light and fluffy.
Melt the butter, then add the orange zest and freshly squeezed orange juice. Stir to combine.
In a separate bowl, whisk together the flour, cocoa powder, baking powder, and salt.
Gradually add the dry ingredients to the egg mixture, alternating with the milk, and gently mix until just combined.
Pour the batter into the prepared cake pan and bake in the preheated oven for approximately 35-40 minutes, or until a wooden skewer inserted into the center comes out clean.
While the cake is baking, prepare the chocolate ganache: heat the heavy cream until just simmering, then pour it over the finely chopped dark chocolate. Let it sit for a minute, then stir until smooth and glossy.
Remove the cake from the oven and let it cool completely. Then, pour the chocolate ganache over the top.
Refrigerate the cake for at least 1 hour to allow the chocolate ganache to set.
Slice and serve, garnished with orange slices or chocolate shavings.
To provide the best experiences, we and our partners use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us and our partners to process personal data such as browsing behavior or unique IDs on this site and show (non-) personalized ads. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Click below to consent to the above or make granular choices. Your choices will be applied to this site only. You can change your settings at any time, including withdrawing your consent, by using the toggles on the Cookie Policy, or by clicking on the manage consent button at the bottom of the screen.