For the first technical challenge of series 6 of The Great British Bake Off, the bakers were asked to make Marry Berry’s Frosted Walnut Layer Cake. This was a nice technical challenge to do, make the Walnut Cake was easy, the tricky part is making the boiled icing frosting, I have never had a frosting like this it sets quickly so you have to work quickly to decorate this cake.
Ingredients:
Walnut Cake:
225g Soften Butter/Baking Spread
225g Caster Sugar
225g Self-Raising Flour
100g Walnuts
4 x Eggs
1 Tsp Baking Powder
Caramelised Walnuts:
100g Caster Sugar
2 Tbsp Water
10 x Walnut Halves
Buttercream:
125g Soften Butter
250g Icing Sugar
2 Tbsp Milk
½ Tsp Vanilla Extract
Boiled Icing Frosting:
2 x Eggs Whites
350g Caster Sugar
4 Tbsp Water
¼ Tsp Cream of Tartar
1. Preheat the oven to 160C/320F/Gas Mark 3. Next line 3 x 20cm cake tins with parchment paper. Then finely chop the walnut halves.
2. In a large mixing bowl add the softened butter/baking spread, caster sugar, eggs, self-raising flour and baking powder. Mix until all of the ingredients have been evenly mixed together.
3. Add the chopped walnuts and fold into the cake mixture.
4. Divide the Walnut Cake mixture into the 3 x 20cm cake tins.
5. Bake for 25-30 minutes, the cakes should be nice and golden brown. The Walnut Cake will also spring back when lightly pressed. Then leave to cool on a wire rack.
6. While the cake is baking make the caramelised walnuts by placing the caster sugar and water in a pan and heat until the sugar turns a copper brown colour (170-180C on a digital thermometer).
7. Then take the caramel off the heat and add the walnuts. Carefully mix them around in the caramel with a fork. Then place the caramelised walnuts to cool on a baking tray lined with parchment paper.
8. Now make the buttercream by adding the softened butter, icing sugar and vanilla extract in a bowl, mix until the ingredients come together and then add a tablespoon of milk, keep mixing until you get a smooth spreadable consistency. You may need to add more milk.
9. Start assembling the Walnut Cake by placing one layer of cake on a plate and then place some buttercream on the cake and smoothen with an offset spatula.
10. Repeat this process for the other Walnut Cake layer. Spread the remaining buttercream over the top of the cake.
11. Next make the boiled icing by placing the eggs whites, water and cream of tartar in a bowl over a pan of simmering water. Mix with an electric whisk, this may take 10-15 minutes, you will need to keep on mixing until the frosting isn’t grainy. If it is still grainy add a tablespoon more of water, this would help.
12. Cover the top and sides of the cake with the boiled icing.
13. Finally decorate the Walnut Cake with the caramelised Walnuts.
