Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake tins or line them with parchment paper. This will help the cakes release cleanly after baking.

In a large mixing bowl, whisk together the eggs, egg yolk, buttermilk, vegetable oil, warm water, and vanilla extract. Make sure all the wet ingredients are well combined and smooth.

In a separate bowl, sift together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Sifting ensures a lighter, lump-free batter.

Slowly add the dry mixture into the wet mixture in batches, stirring as you go. Use a mixer on low speed or a whisk to blend until the batter is fully smooth and slightly runny – this is normal due to the water content.

Divide the batter evenly between the prepared cake tins. Bake in the preheated oven for about 30–35 minutes or until a toothpick inserted in the center comes out clean. Let cakes cool in the tins for 10 minutes, then transfer them to a wire rack to cool completely.

Melt the white chocolate gently in a heatproof bowl over simmering water (double boiler method) or microwave it in short bursts. Once melted, allow it to cool slightly. In a separate bowl, beat the cream cheese until soft, then gradually add in the melted white chocolate and 7.

Once the cakes are completely cool, level the tops if needed. Spread a generous layer of icing between the two cake layers, then cover the top and sides with the remaining icing. Smooth out with a spatula or create soft swirls for texture. Chill the cake slightly before serving for cleaner slices.