Vertically layered cakes (sometimes called vertical stripe cakes) are SO COOL. I’ve made them a few times now and every time I find them way easier than making a usual layer cake since you don’t really need a crumb-coat step. Plus they look amazing!
They look like some serious magical effort has gone into them, but really the whole thing is basically just a short, very wide roll cake sat upright.
I’ve made vanilla and chocolate versions in the past but I also wanted to try out a different flavour. I made this vertically layered carrot cake a last year for my family for our Easter dessert (gotta have carrot cake at Easter) and we all loved it.
I didn’t get round to posting the recipe so I remade it this year for Mother’s day. I also tweaked the recipe slightly to make it bit easier. I had made a carrot puree before and folded that into the batter which worked really well. However, that’s a whole other annoying step to add to cake baking (no one really wants to have to boil and puree carrots, do they?) so I tried it out with very finely grated carrot and it worked perfectly. So in the end, it was better that I remade it anyway 🙂
I kept the filling simple – whipped cream that had a bit of cream cheese mixed in. No sugar in the filling at all since this is a ‘fatless’ sponge cake (i.e. very sweet) with a rich Swiss meringue buttercream (SMBC) on the outside. I attempted to make a cream cheese SMBC but it split as soon as I added the cream cheese soooo that was a lesson learnt! Instead there’s a simple vanilla SMBC on the outside which tastes like a cloudy, buttery marshmallow. There’s a slight tang from the filling too so you won’t miss that classic cream cheese frosting flavour.
I’ve included this grid of images of the assembly process here as it’s a little complicated to explain but actually very easy to do. Imagine that you have one very long, narrow strip of cake that you’re rolling up into a fat coil. That’s essentially how this cake is made (but out of 4 shorter, narrow cake strips rolled up end to end).
Tips for making Swiss meringue buttercream
If you’ve never made Swiss meringue buttercream (SMBC) before, it can seem quite intimidating to make so I’ve got some top tips to make sure it goes perfectly!
- Make sure the butter is softened before you start – the common downfall when it comes to SMBC is the temperature of the butter. If the butter is too cold, it won’t incorporate into the meringue properly so you’ll end up with clumps of butter.
- Make sure the butter isn’t melty/make sure the meringue isn’t warm when you start adding the butter – if the meringue is warm when you add the butter, it will melt as you add it. Having melted butter in your SMBC can make it split. If you’ve added all the butter and beat the mixture for a few minutes and it’s still looking wet and curdled, pop the bowl in the fridge for 5 minutes then try mixing it again – it should be fine!
- Add the butter slowly – you want to add the softened butter a tablespoon or so at a time to really make sure it has time to incorporate before adding more. This is key to getting a properly emulsified buttercream that’s smooth and light.
- Don’t worry if the mixture splits when you’re adding the butter – It always seems to look so good after adding a small amount of butter then dramatically goes downhill after adding about 1/2 of the butter. Don’t panic! Keep mixing and slowly adding the butter. Usually once all the butter has been added and the mix has been beaten for a few minutes, it will come together to make a beautifully soft frosting.
- The frosting is best used immediately after making – yes you definitely can chill SMBC and then bring it to room temp before using (you may need to beat it in a stand mixer to loosen it up a bit). However if you do this, I find that the frosting isn’t quite as fluffy & easy to work with as it once was. Because of this, I try to make the SMBC when I know I’m ready to frost my cake as I don’t enjoy having to carefully temper & re-beat SMBC which has been previously chilled!
Vertical Layer Carrot Cake
For the cake:
- 6 eggs (medium if you’re in the UK, large if you’re in the US)
- 330 g (1 1/2 cups) granulated sugar
- 220 g (2 2/3 cups) finely grated carrot
- 180 g (1 1/2 cups) plain white (all-purpose) flour
- 2 teaspoons ground cinnamon
- 1 teaspoon ground ginger
- 1/4 teaspoon freshly grated nutmeg
- 1/4 teaspoon salt
- 1 teaspoon baking powder
- 1 teaspoon baking soda
- icing sugar (powdered sugar), for dusting
For the Swiss meringue buttercream:
- 2 egg whites (medium if you’re in the UK, large if you’re in the US)
- 110 g (1/2 cup) granulated sugar
- 160 g (3/4 cup) unsalted butter, very soft, cubed
- pinch of salt
- 1 teaspoon vanilla extract
For the filling:
- 250 ml (1 cup) double cream (heavy cream)
- 1/3 cup cream cheese
For the cake:
- Preheat the oven to 180°C (160°C fan / 350°F). Line two 23 x 33 cm (9 x 13-inch) rimmed baking trays with baking paper. Grease underneath and on top of the baking paper with a bit of vegetable oil.
- Place the eggs into a large bowl and use electric beaters to whisk, gradually streaming in the sugar a bit at a time, then continuing to whisk until foamy, pale and thick. You can also do this in a stand mixer with the whisk attachment.
- Add the grated carrot, flour, cinnamon ,ginger, nutmeg, salt, baking powder and baking soda. Gently fold together until combined.
- Divide the batter between the two prepared baking trays, spreading the batter out into an even layer over the whole tray.
- Bake for 12-17 minutes until the cakes are dark on top and spring back when poked.
- Remove the cakes from the oven, flip each one out onto a clean tea towel dusted with icing sugar (powdered sugar). Remove the baking paper, trim off the very edges of the cakes (a pair of scissors is good here. You can eat the scraps!) and dust the cake with more powdered sugar. Starting at the short edge, roll the cake up (along with the tea towel) into a tight log – it should look as though the tea towel is forming the filling of a Swiss roll cake, this stops the cake sticking together as it cools. Leave to cool completely.
Start on the Swiss meringue buttercream about an hour before you’re ready to assemble the whole cake:
- Place the egg whites and sugar in a large, heatproof bowl. Set over a small pan of simmering water, making sure the bottom of the bowl isn't touching the water, and stir often. We want the sugar to dissolve and the whole mixture to warm up. Keep stirring until the mixture measures 71°C (160°F) on a kitchen thermometer.
- Remove the bowl from the heat and whisk until very thick, pale and completely cooled to room temperature (you can do this in a stand mixer with the whisk attachment or you can do this with handheld electric beaters).
- Once completely cool you can start adding the butter. It’s important you do this very gradually and that the butter is soft so that the mixture can emulsify properly.
- With the mixer running on a medium speed, add the butter one or two cubes at a time, allowing them to become completely mixed in before adding a couple more butter cubes. Continue like this until all the butter has been added. It may look like the mixture is starting to curdle before you’ve added all the butter but this is normal, just keep whipping (see notes below for troubleshooting)
- Mix in the salt and vanilla then set this SMBC aside at room temperature while you make the filling…
Make the filling:
- Place the heavy cream in a large bowl. Whip with a whisk until the cream is starting to thicken – it should be fluffy but should still be able to plop off of a spoon (i.e. don’t overwhip it! If it starts to separate because you’ve whisked it too much, you can stir a bit more double cream in and that should help bring it back).
- Beat the cream cheese in a separate small bowl, to soften it up. Stir in a bit of the whipped cream to loosen, then add it all to the large bowl of whipped cream and stir through gently. Don’t overmix.
Assemble (see grid of images above recipe to aid):
- Carefully unroll your cooled cakes from their tea towels and re-roll. Cut each log in half so you have four logs about 4 inches long.
- Unroll one of the logs very gently and spread 1/4 of the whipped cream over the surface of it. Re-roll the same way and stand the rolled log up like a tree trunk.
- Unroll a second log of cake, spread on 1/4 of the whipped cream. Starting at the exposed edge of the ‘tree trunk’, wrap this second strip of cake around it.
- Repeat with the next two cake logs so you end up with a very fat, short roll cake sat upright.
- If your cakes crack/break in the process of doing this, don’t worry about it. Just patch it back together with some filling and you really won’t notice it!
- Place onto a cake stand and frost the top with 1/3 of the SMBC using an offset spatula to smooth it out to the edges. Frost the sides with the remaining SMBC, smoothing out with an offset spatula.
- Chill until ready to serve.
- If the SMBC looks like it is curdling, place the bowl into the fridge to chill the butter for a few minutes. Remove from the fridge and whip again to re-emulsify.