I’m a big fan of Birthdays, especially other people’s as its the perfect excuse to make a giant delicious cake! It was my Mum’s birthday last weekend, and I was really keen to create something that included her childhood love of honeycomb. So, ta dahh! The chocolate honeycomb genoise was born 🙂
My mum used to tell me about her and my uncle’s trips to the cinema when they were little. They’d go to the ‘pictures’ on a Saturday morning, my Nan would give them 2 and 6 pence in old money (12.5p to you and me!) and that’d see them to/from the cinema, buy them both a ticket AND sweets! Its just crazy when you think about it now. I really remember that Mum’s sweet of choice was always a block of honeycomb. No chocolate coating like in the Crunchie you get today, just pure honeycomb.
What’s actually weirder than the crazy low prices is that they would walk into a film halfway through! Films played on a loop back then, so you would watch the film to the end and then watch the start that you’d missed when the film begun again. SO WEIRD.
I wanted to keep the sponge quite light, so I decided to make a genoise sponge. A genoise has hardly any fat and instead includes a lot of heavily whisked eggs to create an airy sponge that can be sandwiched with richer fillings! I wanted to make a more traditional buttercream this time, rather than my fave swiss-meringue, so the lighter sponge seemed perfect. The key to a good genoise, is whisking your eggs enough to get to the ribbon stage where a thick ‘rope’ of mixture falls and dissolves slowly on the surface of the mixture. This required about 6-7 minutes of intense whisking, so I’d definitely recommend an electric whisk otherwise it’ll take you much longer! Who needs the gym right?
The honey buttercream is a proper back to basics recipe – butter and icing sugar. Bam. Done. Except I added a squirt of honey to add to the honeycomb theme. I definitely recommend making this in a stand mixer if you have one, and leaving it to beat for a good 5 minutes at least. It turns so deliciously creamy, obviously you can do this with a hand mixer or just a spatula! Though your arm might be dead after the egg whisking for the genoise…
The honeycomb is actually my favourite part to make, as the science behind it is just so cool! Geek glasses on please; when the bicarb is added thermal decomposition occurs meaning that the bicarb releases carbon dioxide. This is then trapped in the viscous mixture, leaving behind the lattice structure that sets hard. I just think its fascinating! It does mean you have to be pretty quick though, as it starts to set!
I crumbled up the honeycomb and sprinkled it over the middle layer of buttercream which added a really nice texture. The best part about this cake is that even with the honeycomb decoration on top, you’ll be left with a bag full of honeycomb for yourself! You could go wild and chuck it all on top of the cake, or you could melt some chocolate and make your own Crunchies! The possibilities are endless, and as long as you keep it air-tight it’ll last you months. Providing it lasts that long anyway…
The final touch I added was a sugar syrup to keep the sponge moist and light. I didn’t add any flavour to the syrup, though you absolutely could! I really do think it added to the finished cake.
This chocolate honeycomb genoise is a real crowd pleaser and perfect for a celebration! Check out my timelapse video below of how I assembled it!
Chocolate Honeycomb Genoise
- 200 g caster sugar
- 5 tbsp golden syrup
- 2 tsp bicarbonate of soda
- 40 g vegetable oil
- 30 g cocoa powder
- 65 g plain flour
- 4 large eggs
- 130 g caster sugar
- 2 pinches sea salt
- 100 ml water
- 100 ml caster sugar
- 300 g unsalted butter room temperature
- 500 g icing sugar
- 100 g clear runny honey
- To make the honeycomb: Line a 20cm square tin with baking paper and grease the paper with butter. Mix the sugar and golden syrup in a deep saucepan and place over a medium heat. Once all the sugar has dissolved, turn up the heat and simmer until the caramel turns the shade of a copper penny. Immediately add the bicarb, and beat with a spatula to fully incorporate. The mixture will be foaming and very hot, so be careful! Scrape straight away into the prepared tin and leave to harden at room temperature. This will take about an hour. Then smash into pieces ready to sprinkle over the cake.
- To make the genoise: Line the base of two 8" baking tins making sure not to grease the sides. Then preheat the oven to 175C. Sift the cocoa and plain flour into a small bowl and set aside. Add the eggs, sugar and salt to a large bowl and using an electric whisk or stand mixer whisk for 6-7 minutes until tripled in volume, light coloured and a thick rope of mixture falls and dissolves slowly on the surface.
- Add a third of the flour mixture to the eggs and fold with a spatula until almost combined. Then repeat with the other third of flour, and then the final third. Place the oil into a small bowl, and fold in a quarter of the flour/egg mixture ensuring its fully combined. Pour this mixture back into the flour/egg mixture and fold again until all just combined.
- Evenly pour the mixture into both baking tins and bake for 20 minutes until the cake has risen and feels firm to touch. Cool for a few minutes in the tin, and then using a knife scrape around the edges of the cake taking care not to tear the cake. Then invert the cakes out of the tin and place on a cooling rack to cool completely.
- To make the syrup: Place the water and sugar into a small saucepan over a high heat. Simmer until all the sugar has dissolved and set aside to cool.
- To make the honey buttercream: Place the butter into a bowl of a stand mixer or use an electric whisk to beat until smooth and lightened in colour (this will take a few minutes). Add the icing sugar in stages, ensuring it is thoroughly combined between each addition. Finally, add the honey and continue to beat for a further 4-5 minutes until smooth.
- To assemble: Place one of the genoise sponges onto a cake board or serving plate and using a pastry brush dab over half of the sugar syrup.
- Then spread half of the buttercream onto the cake, and sprinkle a layer of honeycomb. Add the second genoise sponge on top, and dab the remaining sugar syrup all over the sponge with the pastry brush. Spread the remaining buttercream on top of the cake, and decorate with more honeycomb.