Rhubarb & ginger Battenberg cake

The power of baking in evoking happy memories of childhood is one of the many reasons baking is such an addiction for me; a Battenberg cake never fails to transport me back to being a child again, when slices of Battenberg were handed out as a real teatime treat.

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I adore Battenberg, and while a coffee and walnut version is my favourite type, and one I make most often, this time I have gone for rhubarb and ginger as the key flavours – flavours which go so well together.

I have made this version several times now over the years, especially at this time of the year using rhubarb I had frozen from last year’s pickings, or in a few months time when the fresh rhubarb comes around again. Mind you I have even used tinned rhubarb of all things! Honestly, it works well here.

Rhubarb & ginger Battenberg cake

 The two sponges

The ginger sponge has stem ginger pieces as well as a few dates: little bursts of sweet heat from the ginger and the lovely squidyness you get from the dates suspended in the light sponge: this actually works well as a cake in its own right.

The rhubarb sponge has puréed rhubarb mixed into it and just the merest touch of red food colouring: now I try to resist using food colouring in cakes but I wanted a pink tinge here.

Rhubarb & ginger Battenberg cake

A rhubarb buttercream: rhubarb syrup all the way!

A buttercream really must carry some flavour other than just butter and icing sugar, so here I made a rhubarb syrup to add to the buttercream as well as some of the puréed rhubarb that then gets sieved to get the smoothest buttercream.

Together you get a lovely intense flavour to the buttercream, with the sharpness, fragrance and flavour of rhubarb coming through the sweetness of the buttercream. You can just use the puréed rhubarb or leave it fairly coarse for extra texture.

Chocolate as the perfect stabilizer in buttercream

The melted white chocolate is used in the buttercream to ensure it remains stable, as it can split or curdle when you add the rhubarb: or, indeed, other flavours for different buttercreams; beating in the chocolate brings it all back together wonderfully.

Rhubarb & ginger Battenberg cake

Rhubarb syrup

To make the syrup using the liquid the rhubarb was poaching in, reducing it with a little sugar to give a fairly thick syrup, that will still have that lovely sharpness.

As I had some rhubarb syrup left I made it into a quick jelly and dotted it over the top, along with some dehydrated rhubarb slices I had made weeks earlier: total over-kill, but why not?

Using tinned rhubarb!

As I mentioned above you can use tinned rhubarb in this cake: it actually works very well. Just let the rhubarb pieces drain fully before puréeing them for use in the cake and/or buttercream. I like to reduce the light syrup it comes in to give an even thicker syrup that makes a superb flavouring for the buttercream.

Rhubarb & ginger Battenberg cake

Recipe: rhubarb & ginger battenberg – makes one cake

Cake:

• 200g self-raising flour, sifted
• 200g caster sugar
• 200g unsalted butter or margarine, softened
• 4 large eggs, at room temperature, beaten
• 100g cooked rhubarb, strained and puréed
• 1 little red food colouring (optional)
• 4 pieces stem ginger, crushed
• 40g dried dates, very finely chopped or crushed
• 1 rounded teaspoon ground ginger
• 1/2 teaspoon mixed spice

Rhubarb buttercream:

• 120g unsalted butter, softened
• 160g icing sugar, sifted
• about 100g cooked rhubarb, strained and puréed, or about 100ml cooled rhubarb syrup (or a mixture)
• 50g white chocolate, melted and cooled

To finish:

• 400g good quality marzipan
• 2 pieces stem ginger, drained and finely chopped
• icing sugar for rolling out and dusting

(1) Pre-heat the oven to 160C (fan) and grease a 20cm square cake tin, and line with a large sheet of greaseproof that has been folded to form a pleat. The greaseproof should be positioned so that the pleat is in the centre of the tin.

(2) Mix together the butter and sugar in a large bowl for a few moments to incorporate them. Add eggs and the flour, and gently mix together until just incorporated: don’t over-beat otherwise you will get heavy sponges. Split into two identical portions, each of which will become the two different sponges.

(3) For the rhubarb sponge, mix the puréed rhubarb and the food colouring (if using) into one of the portions of cake mixture. Pour into one half of the tin and flatten out.

(4) For the other sponge: crush together the stem ginger, dates, ginger powder and mixed spice to form a coarse paste. Mix well into the remaining sponge mixture to distribute evenly and pour into the other half of the tin, flattening out.

(5) Bake for about 25-30 minutes until golden-brown on top and cooked through (a skewer inserted into the cake comes out clean). Leave the cooked cakes in the tin for a few minutes and then carefully invert onto a wire rack to cool. Although the colour of the cake surfaces might not look too different, when they are cut you will see the colour difference very clearly.

Make the rhubarb buttercream:

(6)  Beat the butter and icing sugar for a few minutes until very soft and creamy. Add the rhubarb and white chocolate and beat well to give a light buttercream. Taste, and add more pureed rhubarb or rhubarb syrup if you want it sharper: if the buttercream splits, beat in a little more cooled melted chocolate and it will come back together wonderfully.

Cut the cakes:

(7) Remove the greaseproof carefully from the cake and place one cake on top of the other so that you get uniformly sized cuts. Trim the long edges to neaten them and cut each cake in half length-ways, giving 4 uniformly sized strips of cake. The shorter edges can be trimmed once the marzipan is wrapped around.

(8) Stack the 4 strips of cake in a 2-by-2 arrangement just so you can measure the perimeter around the short edge with a tape measure or string. It should be a bit more than 30cm.

Assemble the Battenberg:

(9) Roll out the marzipan thinly to a rectangle that is a little more than 30cm by 20cm (ie: the width perimeter of the 2-by-2 cake stack and the length of the cake, respectively). Spread some of the buttercream over the centre of the marzipan.

The details are given below, along with several photos of each stage from a coffee & walnut Battenberg I made a while ago, the assembly being exactly the same.

(10) Assemble the sponges by placing one piece of sponge on the buttercream, sticking the other flavour sponge to this with more buttercream. Spread buttercream over the top and repeat with the other two sponges, making sure you alternate the flavour. Push the sponges together firmly so that they hold their shape and spread buttercream along the sides; it doesn’t matter if the icing is not too smooth.

(11) Lift the left “flap” of marzipan over the cake, patting well down against the buttercream. Now lift the remaining “flap” of marzipan over the cake, also patting it well down against the buttercream. Push together any overlap of marzipan and place cake on a plate, seam-side down. Gently flatten the sides so that you have a clear “brick” shape.

(A) Place one piece of sponge on the buttercream

(B) Use a bit of buttercream and stick the alternate flavour sponge to the other

(C) Spread buttercream over the top

(D) Repeat with the remaining two sponges, alternating the colour

(E) Lift up the marzipan “flaps”, using a little more buttercream to adhere to the sponges if needed

(12) With a sharp knife, trim the shorter faces of the cake. It is now ready to serve just as it is, but if preferred you can lightly score the surface of the cake diagonally, pinch the marzipan to crimp the long edges. You can leave as it is or decorate further in any way you want.

Rhubarb & ginger Battenberg cake

Other recipes:

You are limited only by imagination when it comes to Battenberg. Two of my favourites are:

• salted mocha and walnut Battenberg: recipe here
• shocolate and orange Battenberg: recipe here

Salted mocha & walnut battenberg cake

Chocolate and orange Battenberg