01 -
Turn on the oven to 350°F (175°C) and prepare a 9-inch cake pan by greasing it and lining it with parchment. Combine the cocoa powder, sugar, flour, salt, baking powder, and baking soda in a big bowl. Add the eggs, vanilla, oil, and buttermilk, and stir until smooth. Slowly blend in the hot coffee or water—it's normal for the batter to be on the thinner side.
02 -
Pour the batter into your cake pan and bake for around 30-35 minutes. Use a toothpick to check if it's done—if it comes out clean, it's ready! Let the cake sit in the pan for a while (10 minutes should do), then move it to a cooling rack and wait until it's completely cool.
03 -
Warm up the heavy cream in a small pot over medium heat. As soon as it's about to boil, take it off the stove and pour it over the chopped chocolate in a bowl. Wait a couple of minutes for the chocolate to melt before stirring it together until it's silky smooth. Stir in the butter, then let the mixture cool slightly until it's thickened but still pourable.
04 -
Melt the dark chocolate in short bursts in the microwave, stirring each time. Put the melted chocolate into a piping bag or a small plastic bag with the corner cut off. On a baking tray lined with parchment, squeeze the chocolate in a crisscross pattern to create a circular 'nest.' Put it in the fridge for 15-20 minutes until firm.
05 -
Put the cake on a serving plate and pour the ganache on top, letting it drip down the edges. Peel the chocolate nest off the parchment and set it gently on top of the cake. Fill the nest with the eggs or candies, and you're ready to serve!