This Stunning But Easy (We Swear) Cake Will Blow People's Minds When You Slice It

This cake is The One.

The instant I laid eyes on the Lemon and Blackcurrant Stripe Cake in Yotam Ottolenghi and Helen Goh’s latest cookbook, Sweet, I knew I had to try it.

An ultra-impressive confection, it defies expectation by tasting even more delicious than it looks and being easier to make than you'd guess. Each slice is a masterpiece of vertical layers: alternating lush stripes of lemon sponge with tart blackcurrant buttercream. But the magic lies in the fact that to make it, you don’t need to know how to pipe rosettes, candy sugar or temper chocolate — you just need to know how to follow a set of solid instructions. I've made it a couple of times with great success. Here are a few pointers I picked up along the way:

The kitchen tools

Nothing fancy is required. You'll need a mixer, blender or food processor, saucepan, measuring spoons, knife, bowls, large cookie sheet, spatula (regular or offset), parchment, kitchen towel and zester.

The book assumes you have a stand mixer, which is a great tool for the avid baker, but a definite investment. So, if you haven’t made the plunge into ownership yet, this recipe can be made with an electric hand mixer. I tried it both ways and found the results to be very similar. (It will just take longer and require a little more elbow grease without a stand-mixer.)

The cake ingredients

The only specialty ingredient called for is blackcurrants, which are used to make a purée to flavour the icing and drizzle over the finished cake. They can be purchased fresh at select grocery stores and farmers' markets when they're in season (July and August) or frozen where available year-round. If you can’t find them, use mixed berries as advised. (Ignoring my own advice about dutifully following the instructions, I chose blueberries — not mixed berries — for the icing the first time I made this cake, with mildly disastrous results: an unbalanced, aggressively buttery blueberry icing.)

The buttercream icing

A piece of advice: Make the icing first, or even a day ahead. It will streamline assembly when the cake is ready to work with. Just store it in the fridge in a covered container, and let it soften before spreading. (Sweet recommends beating it again to aerate before using.)

The icing isn't hard to make, but the cake cooks so fast that it’s much easier to execute in this order, especially if you’re using an electric hand mixer and can't step away while it's beating.

How to bake and assemble the cake

A page-and-a-half of instructions might look scary, but it's not — I promise.  You're being set up for success with extraordinarily informative and clear instructions. I felt like Ottolenghi and Goh were right there, coaching me through the whole process.

I comfortably made the whole cake in about 2 hours, but you could easily save time on the day if you prepare the buttercream a day ahead.  

1. Spread batter over parchment-lined baking sheet, and bake.

2. Cool for five minutes.

3. Roll the cake in a towel to finish cooling completely.

Allowing the cake to fully cool while rolled up makes it possible to re-roll it without breakage once the icing is added.

4. Slice, ice and roll...

Once the cake roll has cooled completely, the fun part begins! Unroll it (easy), slice it into three panels (easy), frost it all (easy), then roll it — one strip at a time (easy):

5. ... and roll again

After the first strip is rolled, connect it to the second strip and continue rolling until all three strips have been rolled and connected into one giant "jelly-roll" type log.

When you're done, it will hold together well enough to be handled.

6. Flip cake and decorate

Flip the cake end-down on a plate or cake-stand.The rolled layers will face upward (this will create those magical vertical stripes when you slice it).

If you look at the arrows on the image below (the camera looks down at the top of the cake)  you can see where the cake strips connect together.

5. Icing and presentation

The rest is pretty standard. Ice the outside of the cake with the remaining icing and then drizzle the reserved berry or blackcurrant sauce overtop, and finally, dress with fresh berries before popping it it in the fridge. Remember to bring it back to room temperature before serving.

This layer cake is worth stepping out of your comfort zone (because you're actually not stretching it that far), and it will genuinely impress everyone who gets a slice. My cousin (a computer expert who also spends a lot of time in the kitchen) was fascinated by the cake's construction, and needed to see the step-by-step photos I took to understand how it worked.

And the leftovers? Helen* says the cake tastes good the next day — but mine blew everyone away, so not even one slice saw a night in the fridge.

*BONUS: Helen (Goh) liked and commented on my cake on Instagram – so we're basically on a first-name basis (right?).

NOTE: If you purchased the North American version of Sweet there have been several corrections to the recipes based around incorrect conversions from the UK convection oven settings to North American conventional temperatures.  Affected recipes and updates can be found on the publisher’s site.  The book will be reprinted in the spring of 2018, anyone who already purchased one can get a replacement by emailing sweet@tenspeed.com.

Watch: Cooking the Book: Yotam Ottolenghi & Helen Goh