I saw this recipe in my Hummingbird Bakery Cake Days cookbook and knew I had to make it for Joe’s birthday, not only is it the most chocolatey looking thing ever, it also contains salt and loads of calories and fat which is great for a Cystic Fibrosis diet! (not so great for everyone else but who cares, its a birthday!)
I decorated Joe’s cake with a space theme for his 2nd birthday as he’s quite a fan of rockets (some of his first words were “rocket to the moon!) I just used a toy playmobil rocket and space themed candles for decoration, plus piped on a number two decorated with gold balls, and sprinkled blue and white sugar crystal decorations on top to make it look like space rocks and stars.
This cake is quite labour intensive but definitely worth it. I made a two tier version so I made two thirds of the cake mix, but I made full quantities of the caramel and the chocolate frosting and used the extra to decorate some cupcakes at a later date.
For the sponge:
300g unsalted butter, softened
300g caster sugar
140g soft light brown sugar
100g cocoa powder
1 tsp vanilla essence
330g (11½oz) plain flour
2 tsp baking powder
1 tsp bicarbonate of soda
½ tsp salt
For the salty caramel:
200g caster sugar
2 tbsp golden syrup
120ml double cream
60ml soured cream
1 tsp fine sea salt
For the frosting:
200g caster sugar
2 tbsp golden syrup
360 ml double cream
450g dark chocolate (minimum 70% cocoa solids), chopped, plus extra to decorate
450g unsalted butter, softened
Sea salt flakes, for sprinkling
1. First make the salty caramel. In a small saucepan bring the sugar and golden syrup to the boil with 60ml (2fl oz) of water, allowing the mixture to boil for about 10 minutes, during which time it should become quite syrupy and a rich caramel colour.
2. Put the double cream, soured cream and salt in a separate pan and bring to the boil, then remove from the heat. The salt should completely dissolve in the cream.
3. When the sugar syrup is ready, remove it from the heat and carefully add the hot cream. It will bubble up as you pour in the cream, but smooth out again quickly after that, becoming a creamier golden colour. Pour the caramel into a small bowl and set it aside to cool while you make the frosting.
4. In a small, clean saucepan, bring the caster sugar and golden syrup to the boil with 60 millilitres of water, again letting this boil for approximately 10 minutes or until it is syrupy and caramel-coloured.
5. In a separate pan, bring the double cream to the boil. Carefully pour the hot cream into the caramel: as before, it will bubble up, but settle again shortly afterwards. Set this caramel aside to cool slightly.
6. Once it has cooled, add the chopped chocolate, stirring constantly while the chocolate melts. Using a hand-held electric whisk, mix the frosting for about 10 minutes or until the bottom of the bowl feels cool.
7. Add the butter to the chocolate caramel frosting and whisk together until the mixture is light and looks slightly whipped. Place the frosting in the fridge to cool and set for 40–50 minutes while you make the sponge.
8. Preheat the oven to 170°C/gas mark 3, and line the bases of the sandwich tins with baking parchment.
9. Using a freestanding electric mixer with the paddle attachment, or a hand-held electric whisk, cream together the butter and both types of sugars until light and fluffy. Add the eggs one at a time, mixing well after each addition and scraping down the sides of the bowl.
10. In a jug stir together the cocoa powder, buttermilk and vanilla essence with 60 millitres of water to form a thick paste. Sift together the remaining sponge ingredients, then add these in stages to the creamed butter and sugar, alternating with the cocoa powder paste and mixing thoroughly on a low-to-medium speed until all the ingredients are incorporated.
11. Divide the batter between the three prepared cake tins and bake for approximately 25 minutes or until the top of each sponge feels springy to the touch. Allow the sponges to cool slightly in their tins before turning out on to a wire rack and cooling completely before assembling.
12. Once the sponges feel cold to the touch, place one on a plate or cake card and top with approximately two tablespoons of the salty caramel, smoothing it over the sponge using a palette knife. Top the caramel layer with three to four tablespoons of the frosting and smooth it out as before.
13. Continue this process, sandwiching together the other two sponges with the remaining salty caramel and a layer of frosting and leaving enough frosting to cover the sides and top of the cake. To finish, decorate the top with chopped chocolate and a light sprinkling of the sea salt flakes.