Sticky Toffee Cake with Caramelised White Chocolate Buttercream
This sticky toffee cake with Swiss meringue and caramelised white chocolate buttercream, drizzled with salted caramel sauce is gloriously decadent and a real showstopper. The perfect celebration cake based on the traditional dessert, Kris Biggs, Head Baker at Knead Bakery shares his recipe with us.
Kris has been baking cakes and sweet treats for over 15 years, working in boutique hotels, three Michelin restaurants and the best five-star hotels. His new venture, Knead Bakery, is opening in Cirencester.
Sticky Toffee Cake with Swiss Meringue and Caramelised White Chocolate Buttercream and Salted Caramel Sauce
For the sponge:
280g caster sugar
300g self raising flour
250g dried dates
8g bicarbonate of soda
For the buttercream:
120g white chocolate broken into small evenly sized pieces
3 egg whites
200g caster sugar
340g butter at room temperature
Salted caramel sauce:
125g caster sugar
75g whipping cream
A pinch of salt
Preheat the oven to 160°C Fan/Gas 3 and lightly grease two 20cm cake tins.
Begin by making the sponge. Bring the water to the boil and put the chopped dates and bicarbonate of soda into a heat proof bowl. Pour the boiled water over, give it a stir and then leave for 10 minutes. Once softened, blitz with a hand blender until the mixture becomes a smooth puree.
Cream the butter and sugar, beating out any lumps. Beat in the first egg and keep beating – scraping down the sides of the bowl as necessary – until completely incorporated, then do the same with the other eggs.
Beating more gently, add the flour until you have a smooth, thick batter. Add the date puree into the batter and beat gently to mix in.
Pour and scrape the mixture into your prepared cake tins and bake for 30–35 minutes, or until a cake tester comes out clean.
To make the Swiss meringue buttercream and caramelised white chocolate icing:
Preheat the oven to 120°C/gas mark ½.
Spread out the white chocolate onto a shallow baking tray and place in the oven for 10 minutes. Remove from the oven and stir and spread the chocolate around with a spatula. Repeat this process every 10 minutes for 30-60 minutes, until the white chocolate is deep-golden brown in colour.
During this time, the chocolate may turn lumpy and have a ‘chalky’ appearance - this is normal, so keep going. Once the chocolate has caramelised and has reached the correct consistency, allow to cool before chopping into a small pieces.
To make the Swiss meringue buttercream, start by whisking the sugar and the egg whites together, then set the bowl over a saucepan filled with simmering water. Do not let the bottom of the mixing bowl touch the water. Whisk the whites and sugar constantly until the sugar is dissolved and mixture has thinned out. The mixture will be thick and tacky at first, then thin out and appear frothy on top.
To test whether it is ready, you can use your finger or an instant read thermometer. Lightly and quickly dip your finger (it’s very hot, be careful) and rub the mixture between your thumb and finger. You shouldn’t feel any sugar granules. If using a thermometer, the temperature should read 160°F (71°C).
Transfer the warm mixture to the bowl of a stand mixer fitted with a whisk attachment. Beat until stiff peaks form and the meringue is no longer warm to touch, at least 10-15 minutes.
Switch the stand mixer to the paddle attachment and add the butter 1 tablespoon at a time. Wait for the butter to fully mix in before adding the caramelized white chocolate.
Salted caramel sauce
Put a medium sized, non-stick pan over a high heat and pour in the water. Carefully pour in the sugar and bring it to the boil. Cook for 3-4 minutes, or until the sugar starts to turn golden brown – you don’t need to stir but you can gently swirl the pan to make sure all the sugar melts.
Once the sugar has melted and bubbles form all over the surface, take the pan away from the heat. Mix whipping cream and carefully pour it into the pan (be careful to avoid hot splashes). Whisk in the butter and add a good pinch of salt.
Leave the salted caramel to cool before using.
Assembling the cake
Place one cake layer on a cake board or serving plate. Spread 200g of buttercream onto the cake layer with an offset spatula or the back, straight edge of a large knife. Top with a second cake layer, crumb coat* the cake with the Swiss meringue buttercream. Then add the rest of the buttercream into a piping bag with a star nozzle, pipe on top of the cake.
Refrigerate for 1 hour, then add drops of salted caramel in between the buttercream. Grate a little bit of dark chocolate over the cake to finish.
*for a crumb coating guide, Lily Vanilli has a good visual explanation.