A Tunnock’s Birthday Cake

By which I mean, a birthday cake inspired by products made by those wonderful people at Tunnock’s. If you’ve never had the pleasure of trying a Tunnock’s product, I can recommend that you do so poste haste – they’re even available on Amazon, so you have no excuse. My dad has always been a fan of Tunnock’s and so it seemed fitting to make a Tunnock’s cake for his birthday. The three items I took inspiration from for this cake are the Caramel Wafer, the Caramel Log and the iconic Tunnock’s Teacake – I made each into a cake, and stacked them up into a three-tiered masterpiece. Let us begin with a photo of said masterpiece.

The original Caramel Log and Caramel Wafer are pretty similar – layers of wafer and chewy caramel, coated in chocolate, and for the Caramel Log you add an outer coat of toasted coconut. Lovely stuff. My plan for the cake version was to make very thin layers of sponge, in vanilla and chocolate flavours, then to layer them up with wafer and caramel sauce. The last thing was a covering of dark chocolate ganache, because Father Rock Salt prefers the dark chocolate versions, and then a final coating of toasted coconut for the Caramel Log layer. The top cake was teacake inspired – the original Teacake is a biscuit base with a marshmallow resting on top, and a shell of chocolate to finish. My cake version was a layer of biscuit, a layer of marshmallow and a final layer of chocolate sponge, coated in dark chocolate ganache.

Having fully conceptualised the cake (oh yes, I conceptualised it, that’s right), I had only to get to work and make it. This wasn’t as easy as the conceptualising, as you might conceptualise. There were some times when I thought that the kitchen might not recover and that I’d forever more be covered in chocolate ganache. It looked like this for about two days:

Stacks of cake, swathes of baking parchment, an egg carton holding only cracked open eggshells that wouldn’t fit in the already full bin… This isn’t even the half of it. I managed to keep it more or less under control, but there were moments. Oh yes, there were moments alright.

I had decided to bake the cake layers individually, rather than bake two big cakes and slice them into six layers afterwards. Even though I have a great cake cutting wire, I find slicing a cake to be quite a stressful experience. Why I thought baking 13 layers of cake (and one of biscuit) would be less stressful I’m not totally sure… In fact, I think it was – I had more control over the process, and while they didn’t all work out perfectly (see exhibit A) at least I could take steps to correct the problems I did have, whereas when you’ve sliced a cake so that it’s a millimetre thick on one side and an inch thick on the other, there’s not too much to be done.

This is exhibit A:

Exhibit A occurred because I tried to remove it from the baking receptacle before it was cool, and without having lined the tin with baking parchment first. The last cakes were more successful than the first, I learned as I went along. A second problem I found is that the muggy, humid weather we’ve been having left all the sponge layers quite sticky even after they were cool. I know some people don’t give credit to the weather vs baking argument, but I definitely notice a difference. It meant I had to slide layers of baking paper in between them to store them overnight, and even then there were a few moments where it looked like I was going to tear apart another layer of cake and my emotions ran somewhat close to the surface.
To minimise the initial effort of baking six vanilla and six chocolate sponge layers, I made one huge batch of unflavoured sponge mix by the favourite all in one method. This recipe for enough sponge to make two square cakes, one eight inches wide and one five inches wide, each with six thin layers.

• 500g plain flour
• 500g golden caster sugar
• 500g margarine
• 2 tbsp baking power
• 100ml milk
• 5 eggs

I mixed all this together, all at once, until just combined. Then, I weighed the finished product, and split into two. To one half I added a tablespoon of vanilla essence, to the other three tablespoons of cocoa powder. Now, I really should have weighed out each of the layers as I went along, to make sure they were all the same thickness, but I didn’t take it this far. I probably would, another time, but as it was I used a ladle to transfer roughly the same amount into the baking tin each time. You can see that I didn’t get it exactly right in Exhibit B:

Baking all the sponges was the first stage, and took up the first night of baking. I also made the marshmallow for the Teacake cake, following the same recipe as I used to make the Cranachan Marshmallows, and left to set overnight. The second night was to devoted baking the biscuit base, making the chocolate ganache icing and the assembly of all three cakes.

I began by making sure I was ready to assemble the cakes, laying them out in the right order and with the wafers in easy reach, and out of the packet. I filled a glass jug with very hot water so that it would be warm and keep the caramel sauce liquid for longer. Then I proceeded with making a simple caramel sauce, as follows:

• 225g sugar
• 225g butter (real butter, not margarine)
• 200ml milk

First, melt the butter and sugar together until the sugar is dissolved. Continue to heat, stirring, until the sauce thickens and looks paler. It will be giving off big bubbles. Then you can *carefully* add the milk, gradually at first. The sauce will spit and hiss and generally kick up a fuss so watch out for rogue droplets of caramel.

I emptied and dried the jug and poured the sauce into it, then started to layer up the sponge and wafers.

I started with vanilla sponge, added a layer of drizzled sauce, which I spread with the back of a spoon before adding wafers and then a layer of chocolate sponge. Another time I would add another layer of caramel on top of the wafers to fully hold the cake together once it’s sliced. I found that the sauce tended to cool and crystallise just as I reached the end of the process, so don’t dally about it.
Once I had these assembled, I turned to the task of coating them and producing an even finish on all sides and the top. I started with the middle layer, which was Caramel Log themed, because I knew the toasted coconut would camouflage any imperfections and that would let me get a bit of practise.

First I made the ganache, which is also ridiculously simple:

• 300g dark chocolate
• 100g single cream

Melt these together in a bowl over some simmering water, then let cool and thicken a little before using.

I spooned some over the top of the first cake, and used an icing scraper to push much of it over the edges and down the sides of the cake. I then used the same scraper to spread the over-run round the surface evenly. I had intended to try to fill in the gaps at the edges of the layers but couldn’t reliably get this to work. Once I covered the whole lot with toasted coconut, it didn’t really matter though – as predicted!

With the bigger layer, I decided to learn from my first attempt and trim back the edges of the cake to make a flat surface for the ganache to hold to. I used a serrated knife to take a narrow slice off each side – the wafers cut surprisingly easily, I’m glad to report. Once I’d levelled off the sides like this, I used the same technique to coat the cake in ganache – spooning a lot onto the top of the cake, then pushing the excess over the sides and neatening it up once it got there.

Finally, the Teacake cake. I’d made the sponge layer along with all the other sponge, and had set some marshmallow in a tiny cake tin of the same size. The final biscuit layer was made like so:

• 125g plain flour
• 100g golden caster sugar
• 1 1/2 tablespoons cocoa powder
• pinch salt
• 60g unsalted butter, softened and cut into chunks

I mixed the dry ingredients, then rubbed the butter in to give a texture like coarse, wet sand. I pressed this mixture into a tin and baked at 175C for fifteen minutes. This made more biscuit than I needed but it doesn’t hurt to be over-prepared. Once the biscuit was cooled, I cut out a circle using the same size of baking tin that I’d used for the sponge and marshmallow as a guide.

I stuck the three layers together by brushing the top and bottom of the marshmallow with water, then pressing the biscuit and sponge on either side. Marshmallow is naturally veeeeeery sticky. Once assembled, I coated the entire thing in ganache. Done.

Here are my three completed cake layers, perched on the box of an emergency pizza that the G man brought round on night two of the baking:

The ganache set well overnight to a dry, hard finish. It doesn’t crack when you slice it but it also doesn’t melt at room temperature, making it a reliable and easy to make cake covering.
The rest of the process was a matter of stacking and a little writing – I enjoy writing with icing, though I did have a false start with this and have to oh-so-carefully scrape it all off and start over again. I’m proud to say that you can’t tell. Except now you can, because I told you. Oh.

The cake sliced up really well, even the Teacake layer which I was worried would squash down and then explode out the sides, leaving the sponge and biscuit layered together and the marshmallow all up the walls. In fact, it sliced like a dream, and looked gorgeous inside!

Caramel Log cake

Tunnocks Teacake cake

Thus ends my epic tale of an epic cake. I was delighted with how it turned out, both aesthetically and gustationally. Yes, I did just use the word gustationally, but I did not do so with a straight face, I can assure you. There are some minor things that I would change about the appearance – mainly that elusive perfectly flat finish to the icing – but overall it turned out as I’d imagined it, and the flavours were really close to the inspirational chocolate treats made by the experts.

This post has not in any way been sponsored by Tunnock’s, but I will be sharing it with them through their website and I hope they’ll like what I’ve done here (and hire me as a creative consultant, or similar).

Here’s my dad cutting his cake! Isn’t this a great picture?