Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.

In a large mixing bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.

In another bowl, whisk eggs, buttermilk, oil, and vanilla until smooth. Combine wet and dry ingredients until just mixed.

Divide the batter into the cake pans and bake for 30-35 minutes until a toothpick comes out clean.

Remove from oven, let cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

Prepare chocolate ganache by heating cream, pouring it over chopped dark chocolate, and stirring until smooth.

Once cooled, place one cake layer on a plate, add ganache, then top with the second layer. Coat the entire cake with ganache.

Melt white chocolate, pipe into a spiderweb design on top of the ganache using a toothpick to create the web effect.

Let the decorated cake sit for at least 30 minutes before serving for the ganache to set.