The Violet Bubble Cake
A free recipe
The Bubble Cake, one of my personal favourites of all those we make at Violet, is having a bit of a moment. I shared a video of our chefs finishing one on social media, and it’s racked up over 600,000 views. I’ve had messages and emails about it, and the orders have been crazy! I think the beauty of the bubble, and what makes it such an exciting cake, is how whimsical it is while still being simple.
I invented the cake originally for my friend Oliver Hadlee-Pearch who is coeliac, with a gluten free almond sponge and whipped marshmallow bubbles that complimented each other so well with their pillowy textures. Now we make them at the bakery with all sorts of different sponges most days of the week. I’m sharing the recipe for our classic, gluten-full, vanilla bubble cake below to celebrate its newfound celebrity.
Make sure that the sponge is completely cooled before piping the bubbles onto it. Use a 15mm piping nozzle, like this one, and starting low steadily pipe the marshmallow onto the cake before pulling up and swirling the bag to finish. Decorate with a light hand; a dusting of raspberry powder - get some here (or cocoa, of you’re doing it on a chocolate cake), a scattering of flower petals, and some fresh fruit is all you need. It’s the start of the strawberry season in the UK and we’re so excited to be using them.
You’ll also need a 9”x13” cake tin to make this cake - I like this one - and a sugar thermometer really helps. A digital probe style, like this, is great.
Claire x
Vanilla Bubble Cake
for the sponge
500g (2 ½ cups) caster sugar
150g (½ cup + 2 Tbsps) unsalted butter, softened
100g (scant ½ cup) vegetable oil
4 eggs
320g (1 ¼ cup + 1 Tbsp) whole milk
1 ½ tsp vanilla extract
500g (3 ½ cups) plain flour
1 Tbsp baking powder
1 tsp salt
for the marshmallow bubbles
3 egg whites, fresh. If they’re pasteurised won’t whip up properly.
150g (¾ cup) caster sugar
1 ½ tsp golden syrup or fructose syrup
Pinch of salt
1 ½ Tbsp vanilla extract
Freeze dried raspberry powder, fresh flowers, and fresh fruit, to decorate.
To make the sponge, preheat your oven to 150°C fan/170°C/340°F/gas mark 3½. Grease and line a 9” x 13” cake tin.
In the bowl of a stand mixer, cream together the butter and caster sugar, then add the oil and whip until light and fluffy. Add the eggs in two stages, scraping down the bowl each time to just incorporate. Be careful not to overwhip the eggs.
In another large bowl, whisk together the flour, salt, and baking powder and set aside. In a third bowl or jug, combine the milk and vanilla, and set aside.
Add 1/3 of the dry flour mix to the stand mixer, and mix on low while you add 1/3 of the milk. Scrape the bowl down, and repeat until all the ingredients are just combined.
Pour the batter into your prepared tin and bake until the sponge is lightly golden, springs back to the touch, and a skewer inserted in the centre of the cake comes out clean, about 50-60 minutes. Remove from the oven and allow to cool completely in the tin.
Once the cake is cooled, make the marshmallow icing. Put all of the ingredients into the metal or glass bowl of a stand mixer 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). Whisk continuously until the sugar dissolves and the mixture is very warm to the touch. If using a sugar thermometer, whisk continuously for 2 minutes, or until it reads 70-75°C (158-167°F) - whichever comes first. Transfer the bowl to your mixer and whisk on high speed until you almost have stiff peaks.
Put the icing into a piping bag with a 15mm round nozzle (or use a spoon) and pipe (or spoon) large blobs of icing onto the cooled cake. Decorate with a dusting of raspberry powder, fresh fruit, and petals.