This blackberry jam cake is the perfect cake for Autumn. Theres a light cinnamon sponge, sticky gooey blackberry jam and sweet icing made with fresh blackberries! It’s the perfect sweet treat!
In my opinion blackberries are so under-utilised in the UK. I don’t often see blackberry flavoured treats, and hardly ever a jar of blackberry jam on the shelves! But blackberries are so delicious!! I’m definitely trying to include them more in my bakes, and oh boy. Once you make the blackberry jam for this cake you’ll be happy theres extra leftover! It’s SO good. I’ve made two batches of it so far, and my toast has never been happier!
Key Ingredients You’ll Need
- Blackberries – Goes without saying really! But for this you’ll need blackberries for the jam and to make the icing. You can totally use frozen blackberries for both here, if that helps to cut the cost! And personally, I really like using frozen fruit to make jam! I think it still tastes great, and can make preparation that bit easier!
- Jam Sugar – Ripe blackberries like some other members of the berry family aren’t high in pectin, which is what helps jam to set when heated with sugar. You can counter this by using jam sugar, which has pectin already included or add the pectin yourself. You do want a pretty firm set to the jam, as you’ll be adding it directly into the batter.
- Sour Cream – The secret to a moist and tender bundt cake, is sour cream. The high fat content in sour cream helps to shorten gluten strands, which makes for a really light delicious sponge. Which is perfect for a pretty big bundt cake!
How to make blackberry jam cake
I love making a bundt cake, because even with limited decoration they make a great showstopper! They’re simple to put together and last so so well. I’ve included instructions on how to make your own blackberry jam here, but if you want to save time you can use shop bought!
Making blackberry jam
Making jam is very simple, and you don’t need any fancy equipment. Though a thermometer can help – 104.5C/220.1F is the setting point for jam – the saucer trick is something anyone can do! So first step is to pop a small plate or saucer into the freezer. Then pour your blackberries and sugar into a large wide saucepan and stir together.
Then place the saucepan over a medium heat, stirring every now and then until the juice from the blackberries has been released and the sugar dissolved. Then you can turn up the heat and bring your jam to a rolling boil. At this point add a knob of butter; this helps to dissipate any ‘scum’ – the white froth that may appear at the top of your jam. You can also skim it off with a spoon if needed.
I find boiling for 5 minutes, gives me the perfect setting jam. But now we can use our saucer trick to check! Bring the saucer out of the freezer, and spoon a little jam onto the plate. Wait a few seconds, and then drag your finger through the jam. If it wrinkles or leaves a clear line, your jam is ready and you can take it off the heat. If it is still very runny, keep cooking the jam and repeat the saucer trick until set.
You can then pour the jam into a heat-proof bowl to cool while you start making the cake. You will end up with more jam than you need, so you can pour 200g into a sterilised jar, leaving 300g for the cake.
Making the bundt cake batter
This bundt cake batter is very simple, and really delicious – definitely make sure you lick the spoon! But firstly, you need to make sure you properly prepare your bundt tin. As the tin has a more intricate design, theres more chance of your cake getting stuck in the tin, which is NOT what we want. So make sure you grease the tin liberally, and then dust with flour. This combination always ensures an easy release for your cake.
The batter is made using the creaming method – so firstly the butter and sugar must be whipped together until light and fluffy. Then the eggs and vanilla added. The final step is to add the dry ingredients alternating with the sour cream – so dry-sour cream-dry-sour cream-dry. You can do all of this by hand, but I find an electric hand-whisk makes life that little bit easier!
Then you can pour 3/4 of the mixture into the prepared bundt tin. Now, you may notice that the jam appears at the top of the cake in the pictures, but we’re actually adding it at the bottom of the cake batter. Through the cooking process the jam will sink as its heavier than the batter, but what you need to do is ensure it’s encased by the batter.
So, make a shallow trench in the batter already in the tin, and pour the jam in, making sure it’s even. Then spoon the remaining 1/4 of cake batter on top and level out. Then you can bake!
Making the fresh blackberry icing
Once your bundt cake has been baked, you need to let it cool inside the tin for at least 45 minutes or so before turning it out. The cake needs this cooling time, to firm up enough to stand well on its own. As the jam is quite wet and heavy, it can make the cake collapse if you turn it out too soon. I learnt that the hard way!!
Once the cake has completely cooled, you can pour over the icing. This icing is so simple, but SO effective. Just blitzed fresh blackberries, sieved and combined with icing sugar. Like seriously, can you believe that colour is natural?! I love how vibrant fresh fruits can be! You don’t need anything artificial at all!
Once the icing has set for a few minutes, you can dig in and devour!
Tips & Tricks
Short answer? No. Sorry 🙁 The hole in the centre of the cake helps to evenly distribute the heat when baking, so if you put this batter into a regular tin it might not cook in the middle!
Jam is usually made with a 1:1 ratio of fruit to sugar. If there’s too much fruit to sugar, you’ll lose some of the preservation effects from the sugar and it could make your jam quite tart. If you really want to reduce the sugar, I would recommend using a recipe designed for a reduced sugar jam or purchasing one in the shops, rather than just reducing the sugar in my recipe.
The cake will be golden brown, and a skewer inserted into the cake should come out clean.
I really love this blackberry jam cake; its so light and moist, with just a touch of cinnamon. Tender but still gooey from the jam and has just the right amount of sweetness from the icing. It’s also so simple to make, and leaves your kitchen smelling wonderfully autumnal. I really hope you love it as much as I do!
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Blackberry Jam Cake
- 350 g blackberries fresh or frozen
- 350 g jam sugar
- 1 knob of butter
- 180 g unsalted butter room temperature
- 335 g caster sugar
- 4 large eggs
- 1 tsp vanilla extract
- 375 g plain flour
- 3 tsp baking powder
- 1 tsp bicarbonate of soda
- 1 tsp salt
- 1 tsp ground cinnamon
- 225 g sour cream
- 100 g blackberries fresh or frozen but defrosted
- 200 g icing sugar
- For the jam: Firstly, place a small plate or saucer into the freezer. Then place the blackberries and sugar into a large wide saucepan and stir together. Place over a medium heat and stir every now and then until the sugar has dissolved and the juice from the blackberries has been released. (This may take 4-5 minutes if you use frozen berries.) Then turn up the heat and boil for 5 minutes. Add a knob of butter to help dissipate any scum, (you can also skim it off with a spoon).
- Check the jam is set by removing the saucer from the freezer, and placing a teaspoon of jam onto it. Leave for a minute or so, then drag your finger through the jam. If if wrinkles and leaves a clear line, then the jam is set and you can take it off the heat. If not, continue boiling for a few minutes and check again. Then pour the jam into a heat proof bowl to cool. (You will only need to use 300g of the jam, so you can place the remaining 200g into a sterilised jar. You can sterilise clean washed jars for 15 mins at 150C/130C Fan/Gas Mark 2.)
- For the cake: Firstly, grease and flour a Bundt tin and set aside. Then preheat your oven to 175C/155C Fan/Gas Mark 4. In a large bowl, using an electric hand-whisk, cream together the butter and sugar until light and fluffy. Then mix in the eggs one at a time, and then add the vanilla. Combine the flour, baking powder, bicarbonate of soda, salt and cinnamon in a small bowl. Then mix into the batter in 3 increments, alternating with the sour cream between each.
- Pour 3/4 of the batter into the prepared tin, and make a little trench in the middle all the way around. Spoon the 300g of jam into the trench evenly, ensuring that the batter (and not the jam) is touching the centre and edge sides of the tin. Then spread the remaining batter carefully over top, so you cannot see the jam anymore. Bake for 50 minutes, until a skewer inserted comes out clean. Then leave the cake to cool in the tin for at least 45 minutes, before removing and placing on a cooling rack to cool completely.
- For the icing: Blitz the blackberries in a food processor. Then strain, and discard the seeds and pulp, leaving just the juice behind. Place the icing sugar in a large bowl and stir in the blackberry juice (should be about 45g) until you have a thick icing. Pour icing over cooled cake, so it drips down each side.