GBBO 2017 Week 1 - Showstopper - Roasted White Chocolate and Blueberry Pancake Cake

For the third challenge of Cake week, I actually made the cake before I saw the episode. I was too excited. It turns out one of the bakers had the same idea as me! The showstopper challenge was an illusion cake, i.e. a cake that doesn't look like a cake. I don't make many novelty cakes, so wanted to test myself.

What I ended up baking was a stack of pancakes - or is it? It's a simple but delicious Victoria sponge, which I filled and lightly frosted with a roasted white chocolate and blueberry buttercream. I then covered the cakes with fondant and painted them to look like the pancakes. Fun and not as difficult as it looks. Plus it tasted great.

I used hen eggs for the sponge but like previously (see here), I prefer using duck eggs when I get hold of them. The sponge tasted great with hen eggs but even better with ducks.

I've seen roasted white chocolate on some other cooking shows, and have wanted to make it for a while. Simply it involves slowly baking chocolate in an oven until it is golden. It tastes just like white chocolate chips in a fresh cookie, when the chips have turned a little brown on the outside. Even if you don't make the cake, try roasting a bit of white chocolate - you'll be amazed.

I also made a blueberry jam with frozen blueberries. It was really quick and added an extra dimension to the buttercream. This recipe makes about twice what you'll need for the cake - use the rest as a delicious toast topping :)

Makes one 20cm cake

Ingredients:

For the cake:

• 250g (1 cup) butter, melted
• 250g duck eggs (around 4) or equivalent weight of hen eggs
• 250g (1 cup) golden caster sugar
• 250g (2 cups) self-raising flour
• 1 tsp baking powder 
• 1 tsp vanilla extract

For the buttercream:

• 150g (3/5 cup) butter, softened
• 300g (1 & 1/2 cups) icing sugar
• 1 tsp vanilla extract
• 1 tbsp milk
• 150g (1 cup) white chocolate

For the blueberry jam:

• 200g (2 cups) frozen blueberries
• 1 tbsp lemon juice
• 50g (1/5 cup) caster sugar

To finish:

• 600g (around 5 cups) fondant icing
• Icing sugar, for dusting
• Concentrated gel food colourings, yellow, red, ivory, blue and violet

Method:

1. Preheat the oven to 180c (160c fan)/ 355f/gas mark 4. Grease and line the base of two loose bottomed (or springform) 20cm round cake tins.

2. Whisk the eggs in a large mixing bowl. Pour in the sugar and keep whisking for 3-5 until the mixture is pale and has at least doubled in volume (you can use an electric whisk at this stage if you like).

3. Whilst whisking, pour in the melted butter and vanilla extract. Once all of the melted butter has been added, sift in the flour and baking powder.

4. Fold the flour into the batter with a large metal spoon, just until you can see no more pockets of flour. As soon as this happens, evenly distribute the cake batter between the two cake tins.

5. Bake for 25-30 minutes, or until the tops of the cakes are golden, they are starting to pull away from the sides of the tin, and a skewer entered into the centre of the cake comes out clean.

6. Leave to cool for 5 minutes in the tin, then turn out onto a wire rack to cool fully.

7. To make the buttercream, beat the butter in a large mixing bowl with a wooden spoon until it is very soft (it will appear like a soft spread). Sift in half of the icing sugar and keep beating to incorporate the icing sugar.

8. Sift the other half of the icing sugar into the bowl, along with the vanilla extract and 1 tablespoon of milk. Beat until all of the icing sugar has been incorporated. If the mixture appears to thick (it is very hard to beat), add a little more milk (a teaspoon at a time). If when you spoon some buttercream out of the bowl, it immediately falls off the spoon, the mixture is too slack - if this happens add a few tablespoons of icing sugar. You want a spoonful of buttercream to slowly fall off the spoon, and to be spreadable.

9. To make the blueberry jam pour the frozen blueberries, sugar and lemon juice in a saucepan and heat for 5 minutes, until the blueberries are breaking down and the jam coats the back of the spoon. Break down with the back of a spoon and set aside to cool.

10. To roast the white chocolate, preheat the oven to 130c (120c fan)/265f/gas mark 1/2. Line the base of a baking tray with baking parchment. Chop the white chocolate as fine as you can, then scatter over the baking tray.

11. Bake for 5 minutes, then take out of the oven and stir the mixture, moving the white chocolate on the outside to the inside. Bake for another 5 minutes, and stir again. Repeat the baking and stirring until the white chocolate is a light brown colour. Set aside to cool, then chop finely.

12. To finish the buttercream, add the chopped roasted chocolate and a few tablespoons of the jam, so that it's a nice purple colour.

13. To assemble the cake, place a spoonful of the buttercream on the cake tray/serving dish. Use a serrated knife to level the top of the cake if needed. Place the first sponge cake on this buttercream and press down gently. This will stick the cake to the tray.

14. Spread on a thin layer of blueberry jam, and top with half of the buttercream. Use a palette knife to evenly spread the buttercream over the top of the cake. Top with the other levelled sponge.

15. Cover the top and sides of the cake with the remaining buttercream - this gives the cake the crumb coat, and will allow the fondant to stick to the cake. Set the cake aside whist you prepare the fondant.

16. Knead the fondant icing lightly until it is easy to work with. Set aside 150g of the fondant. Take around 75g of fondant and mould into a ball. On a lightly dusted surface use the palms of your hands to roll the fondant into a long cylindrical tube, about 1cm wide and 30cm long. Press the top down slightly then pick up and press around the edge of the cake, touching the cake board.

17. In a little bowl, add a splash of water and add small amounts (by placing toothpicks in food colouring) of the brown, yellow, and red food colouring, to make a deep orange wash colour. Use a paintbrush to paint this over the top the fondant tube you've just placed on the cake, and come about half the way down the side.

18. Roll out the next tube of fondant and lie this on top of the first piece of fondant. Paint the dark orange wash on the fondant as previously. Repeat this process until you're at the top of the cake.

19. Roll out 125g of the reserved fondant on a floured surface (or silicon mat) until it is about 22cm in diameter (so that it covers the top of the cake and there's around 1cm extra around the cake).

20. Place on the top of the cake, then paint over the orange food colouring. This is a good tip I found out - get a piece of kitchen towel, and dap the top of the "pancake" - this gets rid of the paintbrush streaks and looks really cool!

21. Make a light orange glaze with yellow and ivory food colourings and a splash of water. Paint this over all the white fondant currently on the cake. You can now touch the cake up as you like to get the balance of dark orange and yellow.

22. Finish the cake off by colouring two thirds of the remaining fondant with some blue and violet food colouring until you get the perfect shade of purple for a blueberry. Form little balls, then use a toothpick to draw a cross in each "blueberry". Scatter across the cake.

23. Colour the last bit of fondant with yellow food colouring. Roll out thinly and cut out two 3x2cm rectangles. Place this on the cake to be a little butter. You're now done!

24. Enjoy!