Heat the oven to 180°C, 160°C fan, gas 4. Line the base and sides of two 18cm deep sandwich tins (not loose-based) with baking paper.
In a large bowl mix together all the dry ingredients. In a second bowl whisk together the eggs and Hazelnut Chocolate Spread until smooth, then whisk in the buttermilk, vanilla, and vegetable oil.
Beat the liquid into the dry ingredients until smooth. Now pour in 200ml boiling water and whisk again until smooth. The mixture will look thin, but don’t worry.
Divide the cake mix between the lined tins and bake for 25 minutes. Cover loosely with foil and bake for a further 10-15 minutes. Test with a skewer.
Cool in the tins before turning out.
Sandwich the cakes together with a third of the Hazelnut Chocolate Fudge Frosting. Then coat the top and sides with the remainder. Chill for 30 minutes.
Meanwhile, line two baking trays with baking paper. Spread the melted white chocolate into a thin layer on both trays and sprinkle with the nuts and gold sprinkles. Leave to set, cut into long triangular shards then chill.
Press the cold shards onto the cake sides using a little extra Hazelnut Chocolate Spread.
The recipe above makes a two layered cake. If you wish to make a triple layered showstopper (as in photograph above), simply halve the ingredients and make an extra third layer. Make 1 ½ quantities of frosting.
The finished cake will keep in the fridge for 5 days. Allow an hour at room temperature before serving. It also freezes well.
