Instructions

1. Preheat the oven to 180°C/350°F/gas 4. Grease two 20cm/8inch cake tins and line the bottoms with parchment paper.

2. For the cake:

3. Sieve together the flour, cocoa powder and raising agents in a large bowl. Whisk in caster sugar and salt. In a medium sized jug, whisk together the wet ingredients except the boiling water. Add to the dry ingredients and mix with a whisk or electric mixer until mixture is smooth. Slowly add the boiling water and mix until well combined. Batter will be very liquid. Divide batter evenly between prepared cake tins and bake until a toothpick inserted comes out clean, about 25-35 minutes. Remove from oven and leave to cool completely on a wire rack, still in their tins. Before decorating, turn out from tins and remove parchment paper.

4. For the icing:

5. Beat the butter in a large bowl with an electric mixer until smooth. Add the icing sugar and milk and beat until well mixed. Beat in Nutella and salt.

6. To assemble:

7. Place one layer of cake on a serving plate then evenly spread half of the Nutella icing with a spatula neatly to the edges. Place the second sponge layer on top and spread the remaining Nutella icing neatly to the edges. Strew Smarties on top, starting from the outside edge and working your way in. Sprinkle smaller chocolate beans over the Smarties, if using, then place the candles.
8. Remove candles before serving and use a sharp knife to cut slices, cleaning the knife between each cut.
9. Cake will keep for 4-5 days in an airtight container.