Start by melting the white cooking chocolate, heavy cream, unsalted butter, and glucose syrup together until smooth.

Preheat your oven to 150°C (300°F) and grease and line two 8-inch cake tins with parchment paper.

Mix the cooled melted chocolate ganache with sour cream, vegetable oil, and vanilla extract until well combined.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt until combined.

Whip the large eggs and caster sugar together using a mixer until pale and tripled in volume, about 5-7 minutes.

Gently fold the dry ingredient mixture into the egg mixture and then add the chocolate ganache mixture until just combined.

Divide the batter evenly between the prepared cake tins and bake for about 40 minutes or until a skewer comes out clean.

Once baked, cool the cakes in the tins for 10 minutes, then transfer to a wire rack to cool completely.

Use the ganache to frost the layers and decorate with chocolate curls.