Chocolate Bubble Cake

This impressive looking cake is a speciality of Claire Ptak’s of Violet Cakes located at 47 Wilton Way in London.

Chocolate Bubble Cake

SERVES

20

PEOPLE

PREP TIME

20

MINUTES

COOKING TIME

60

MINUTES

Ingredients

  • For the cake 

  • 330g plain flour 

  • 150g cocoa powder 

  • 1½ tsp fine sea salt 

  • 2¼ tsp bicarbonate of soda 

  • 1½ tsp baking powder 

  • 520g caster sugar 

  • 3 eggs 

  • 1½ tsp vanilla extract 

  • 300g plain yoghurt 

  • 150g vegetable oil 

  • 340g hot water 

  • For the marshmallow icing 

  • 5 egg whites (200g) 

  • 340g caster sugar 

  • 50g golden syrup 

  • A pinch of fine sea salt 

  • 1½ tsp vanilla extract 

  • To decorate 

  • Gold leaf (optional) 

  • Fresh flower petals, for example Marigolds and/or Johnny Jump Ups (little Pansies) 

Method

  1. Preheat the oven to 160˚C/ Gas Mark 3/ Fan 140˚C. Butter and line your cake tin with enough greaseproof paper to come up the sides of the tin, this will help to remove the cake later. 

  2. Measure the dry ingredients, including the sugar, into a large mixing bowl and whisk with a balloon whisk to distribute the salt, bicarbonate of soda, and baking powder evenly throughout the other dry ingredients. 

  3. In another bowl, whisk together the wet ingredients (except for the hot water). 

  4. Make a well in the centre of the dry ingredients and pour in the wet mixture. Starting in the middle of the bowl, whisk in a clockwise, circular motion. Don’t switch direction or you’ll end up with lumps. Gradually whisk together until you have a smooth but thick batter. 

  5. Whisk in the hot water until smooth. 

  6. Pour the batter into your pan right away and bake for 50-60 minutes until the top is springy to the touch and an inserted skewer comes out clean. 

  7. Allow the cake to cool completely in the tin. 

  8. Once the cake has cooled, prepare the marshmallow. Have your mixer ready with a whisk attachment. 

  9. Measure all of the ingredients into a metal bowl and place over a saucepan of boiling water (do not let the water touch the bottom of the bowl or it will cook the egg whites). 

  10. Whisk continuously until the sugar dissolves and the mixture is very warm to the touch. Use a thermometer and whisk continuously until it reads 72°C or 70°C (162˚F or 158˚F) for two minutes, whichever comes first. Transfer the mix into the bowl of your electric mixer and whisk on high speed until nearly stiff peaks form. 

  11. Put the icing into a piping bag with a large round nozzle and pipe 20-24 big bubbles in rows over the top of the cooled cake. Use a tiny sieve to dust a strip of cocoa powder lengthwise across the cake. Decorate with flakes of gold leaf and a scattering of fresh flower petals. 

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