Sometimes I get the urge to bake something utterly over the top, this time, I wanted to make something GREEN...The cake stash was getting low so I knew that it had to be some form of cake...What's green...? Mint. What goes with mint...? CHOCOLATE! So....mint choc chip chocolate zebra cake was born. The cake itself is an impressive looking hidden design of alternating layers of chocolate and peppermint sponge, covered in mint choc chip buttercream and topped with chocolate ganache and peppermint chocolate bark. Minty chocolate heaven.
The zebra cake technique is actually quite simple to achieve, you simply dollop alternating colours of batter on top of each other in the tin, use about a heaped tablespoon of batter each time and don't be tempted to spread or level the batter, it will level itself. The cake mix needs to be fairly liquid, but not runny, for this to work; so the mix is made with sunflower oil instead of butter, with some milk and plenty of eggs to create the right consistency. You can use any other flavourless oil in place of the sunflower oil if you prefer. I flavoured one half of my batter with cocoa powder and the other with peppermint extract and coloured the mint mixture (lurid!) green, but you can use any flavours and colours that you like, if you omit the peppermint and green colouring you will be left with chocolate and vanilla mixtures, add your choice of extract and colour to the vanilla mix. The use of oil not only makes sure that the mix is the right consistency to spread, it also ensures that the cake is lovely and soft and moist.
The buttercream tastes just like mint choc chip ice cream, which happens to be Damian's favourite ice cream flavour. I added some double cream to it to make it smoother and give it more of a creamy flavour, I also used a small amount of green colouring to make it look the part, just like the ice cream. Make sure that you chop the chocolate really finely, else you will find the buttercream difficult to spread. I simply chopped it up with a sharp knife, I did attempt to do it using a food processor but I found that it just reduced some chocolate to a powder while leaving the rest in big chunks, you may have better luck.
The peppermint chocolate bark is an unnecessary extra, but it is very tasty, simple to make and looks quite impressive cut into shards and piled on top of the cake. It will also keep well and is the kind of thing that would be good to have around at Christmas ( yes I'm already thinking about Christmas...I made my Christmas pudding a month ago...). You simply melt some dark chocolate and spread it out on some greaseproof paper on a tray, freeze it until it is set, then melt some white chocolate and add peppermint extract and green gel colouring and spread it on top of the dark chocolate, grate over a little more dark chocolate then freeze until set before slicing into shards with a sharp knife.
I didn't manage to take very good photos of the cake as the weather was miserable when i baked it so the lighting was terrible! So these pictures don't quite do it justice.
(Please note: although I have provided a conversion from grams to US cup measurements I cannot guarantee the accuracy as I do not bake using cups, I thoroughly recommend investing in a digital metric scale, it is far more accurate.)
For the cake:
- 250ml (1 cup + 2tsp) sunflower oil
- 250g (1 + ¼ cups) caster (superfine) sugar
- 100ml (⅓ cup + 1tbsp + 1tsp) milk
- 4 eggs
- ½ tsp vanilla extract
- 325g (2 + ¾ cups) self-raising flour, sifted, divided
- 1 tsp baking powder, divided
- 25g (¼ cup) cocoa powder, sifted
- 1 tsp peppermint extract
- green gel food colouring
For the mint chocolate bark:
- 50g (1 + ¾ oz) dark chocolate plus a little extra for grating
- 75g (2 + ½ oz) white chocolate
- couple of drops of peppermint extract
- green gel food colouring
For the buttercream:
- 200g (¾ cup + 2tbsp) softened butter
- 400g (4 cups) icing sugar
- 100ml (⅓ cup + 1tbsp + 1tsp) double cream
- 1tsp peppermint extract
- green gel food colouring
- 50g (1 + ¾ oz) dark chocolate, very finely chopped
For the ganache:
- 75g (2 + ½ oz) dark chocolate
- 75ml (⅓ cup) double cream
- 15g (1tbsp) butter
Preheat the oven to 180°C/350°F/Gas Mark 4, grease two 20cm round loose-bottomed cake tins and line the bases with baking parchment. Put the oil, sugar, milk, eggs and vanilla extract in a large bowl and beat to combine, it is best to do this by hand rather than with an electric mixer as you do not want to incorporate too many air bubbles in this cake.
Pour half of the mixture into a separate large bowl (there should be about 400g in each bowl). Add 175g of the flour, ½ tsp of baking powder and the peppermint extract to one of the bowls, mix well then add enough food colouring to create your desired shade.
Add the remaining 150g flour and ½tsp baking powder to the other bowl, along with the cocoa powder and mix well to combine.
Blob about a tablespoon of the chocolate mixture into the centre of each of the tins, then, using a clean tablespoon, put a blob of the peppermint mixture in the middle of the chocolate one.
Keep doing this, alternating between mint and chocolate, so you form a type of ‘bull’s eye’ or ‘target board’ look. Each time you dollop a blob in, the whole mix will spread out on the base. By the time you have used up both of the cake mixes, they should have reached the edge of the tin. Don't be tempted to level it or encourage the mixture to spread, it will find it's own level.
Place the tins in the centre of the oven on the same shelf and bake for 35-40 minutes (check after 25) until well-risen and a skewer inserted comes out clean. Leave to cool in the tin for a couple of minute then turn out onto a wire rack to cool completely.
To make the mint chocolate bark, melt the dark chocolate, either in a heatproof bowl over a pan of simmering water or in ten second bursts in the microwave. Place a piece of greaseproof paper on a small tray and spread the chocolate out on it into an approx 10x10cm square, place in the freezer until set, this should only take a couple of minutes. Melt the white chocolate with a couple of drops of peppermint extract in the same way as the dark, stir in a teeny amount of food colouring to make it a pale mint green colour, then spread it out on top of the dark chocolate, grate over a little more dark chocolate then return to the freezer to set.
To make the buttercream, beat the butter using an electric whisk until it is very pale and fluffy, sift in the icing sugar, add the cream and peppermint extract and continue to beat until smooth. Add the food colouring a little at a time until you reach a pale mint green colour; stir in the finely chopped chocolate.
Once the cakes are completely cold, trim the tops to level them slightly, then use about a third of the buttercream to sandwich them together, spread the rest over the top and sides then place the cake in the refrigerator while you make the ganache.
Break the chocolate into small pieces and place in a heatproof bowl along with the cream and butter, place the bowl over a pan of simmering water, don't let the water boil or touch the base of the bowl, and stir until melted together. Leave to cool for a minute, you need the ganache to still be fairly runny, but not so hot that it melts the buttercream.
Pour the ganache into the centre of the top of the cake and use a spatula to encourage it towards the edges so that it drips over the sides. Cut the bark into shards using a sharp knife and arrange them on the top of the cake.
(Zebra cake recipe adapted from Lorraine Pascale, Fast, Fresh and Easy Food)