blackberry swirl cake

IMG_8950IMG_8945I am biased* but this is my favourite time of year. The sky takes on a different shade of blue, contrasting perfectly with all the orange of the falling leaves, and it’s usually pleasantly warm, not-quite-coat weather, that no one quite expects {even though it happens every year} which makes it even better.IMG_8928The boyf and I headed out a couple of weekends ago on a favourite walk to a nearby village, Tupperware in tow. Between us we managed to pick around 2 kilos of blackberries during a couple of hours. Seeing as this walk normally takes around 20 minutes, it was blissful – nearly meditative – to just wander along, with the sound of other walkers’ conversations and birdsong in the background and focus on picking the best berries. IMG_8938Our fridge is now full of jam so if you’re on our Christmas list be prepared 😉


My primary reason for collecting berries was that we had a Macmillan coffee morning at work a couple of days later. This recipe is adapted from a Raspberry Ripple cake which I’ve made before and loved, and I had an autumnal version in my head that I thought would be perfect for a bit of fundraising.IMG_8954

Blackberry Swirl Cake

Baked for a Macmillan coffee morning in September 2018

  • This recipe has been modified slightly from the Raspberry Ripple cake recipe in Cupcake Jemma’s ‘The Cake Book’.
  • I baked the mixture as two 8″ (20cm) round cakes and one 6″ cake.
  • I made the blackberry sauce as per Jemma’s recipe, but decided I wanted a more concentrated flavour to put in the buttercream, so boiled some of it down into a thick paste


Blackberry Sauce:
  • 480g blackberries, washed
  • 120g caster sugar
  • 375g soft, unsalted butter
  • 375g caster sugar
  • 6 large eggs {room temp.}
  • ¾ tsp vanilla extract
  • 4½ tbsp milk
  • 19g baking powder + 356g plain flour {or 375g self-raising flour}
Blackberry Buttercream:
  • 250g soft, unsalted butter
  • 340g icing sugar
  • 2 tbsp blackberry paste {see below}
  • zest and juice of half a lemon


Blackberry Sauce:

Heat the blackberries and sugar together in a saucepan on medium heat and bring to the boil. Mash the berries slightly and leave the mixture to bubble away and reduce down. Once you’re happy with the consistency,  pass through a sieve and leave the sauce to cool down.

I then tipped the seeds and pulp out of the sieve and into a bowl, and mixed some water through it. I strained this back through the sieve into a saucepan and boiled this on the stove until I had a very thick, concentrated blackberry paste to use in the buttercream.


Preheat your oven to 180*C and cut out circles of greaseproof paper to line your tins.

Cream together the butter and sugar in a large mixing bowl for 5-7 minutes. Beat in the eggs one by one.

If it looks like it’s beginning to curdle, beat in a tablespoon of the flour. Sieve together the rest of the plain flour and baking powder, then fold this all gently through the wet ingredients.

Mix together the milk and vanilla extract and then fold these through the mixture too.

Divide the mixture between your tins, before spooning some blackberry sauce onto the tops of each. Use a toothpick to swirl it through.

Bake the 8″ cakes for approx. 20-22 minutes, checking with a skewer. My 6″ cake, which was much deeper, took around 40 minutes to bake completely.

Leave the cakes to cool.

Blackberry Buttercream:

Beat the butter until it’s pale – around 5 minutes. Mix in the icing sugar, slowly to begin with, then on high for a few minutes until the buttercream is light and fluffy.

Add the blackberry paste and beat until the colour is even. Taste it, and if you want to make it more tangy as I did, add lemon zest and some juice until it tastes good to you.


Use a cake leveller to make the 8″ cakes flat / divide the 6″ cake into two layers. Spread each layer with remaining blackberry sauce, then blackberry buttercream.

If desired, use a star tip nozzle to pipe rosettes around the top {this uses up quite a lot of buttercream, so do it last}. Decorate with miniature gold sprinkles and more blackberries, if desired.

*biased because it’s my birthday in October! 🎉

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