The first Technical Challenge of Bake Off 2019 was to make 6 of Prue’s Angel Cake Slices, a retro English cake.  Prue’s Angel Cake Slices consist of 3 layers of genoise sponge flavoured with lemon, raspberry and vanilla, sandwiched together with an Italian meringue buttercream and topped with feathered fondant icing. In my typical style, I decided to reinvent the challenge and bring it into the 21^st century with an Asian twist; these are my Black Sesame and Matcha Angel Cake Slices!

I use black sesame powder for the sponge which is essentially ground up toasted black sesame seeds. Black sesame has a smoky nutty bitter flavour to it and it can take a bit of getting used to and similarly, matcha has an earthiness that isn’t everyone’s cup of tea (pun intended). This makes these angel cake slices quite mature and adult in flavour, as well as modern! For the layers, I use two layers of black sesame sponge and a single layer of matcha sponge, which has a nice colour contrast.

Prue’s recipe calls for a large rectangular tin to be split into 3 using foil-lined parchment but I say this is way too much hassle; baking a shallow sponge in a loaf tin does the same trick and you are guaranteed to get 3 sponges of the same size, but not necessarily the same height. This does mean you need to make 3 different batters but I think that’s easier that weighing and dividing a larger batter and working with each one individually. For reference, my loaf tin is a Kaiser 25cm loaf tin but you can also use a 1lb loaf tin and you might want to adjust the baking times; check out Philip’s Blackberry and Lime Angel Cake Slices recipe post as he used a 1lb loaf tin too!

The premise of a genoise sponge is whisked eggs and sugar, usually over heat to increase the volume but an electric whisk does the job perfectly, until it reaches ribbon stage, meaning you can lift the whisk out of the mixture and draw a figure of eight that sinks back into the mixture 2 or 3 seconds later. Then you fold in the flour and melted butter, which makes a genoise different from a sponge used from a Swiss Roll, which is fatless. I stick to tradition and use plain flour for the genoise sponge and not self-raising, relying only on the air from the whisking stage.

Your instinct may be to add the melted butter into the batter straight away and try to fold it in however this is not the best way. Because the consistencies of the cake batter and the melted butter are so far apart, combining the two together straight away leads to overworking the batter and deflating all the air incorporated in the whisking stage. The better technique is to remove some of the cake batter and mix the melted fat into the smaller quantity of batter, bringing the consistencies of both mixtures closer to each other, making mixing the two together easier and so less air is lost.

I used a genoise sponge which containing toasted hazelnuts in my Cake Week bake for last year’s Bake Off Bake Along: check out my Hazelnut & Coffee Traybake recipe! Also check out my video guide on how to make my Angel Cake Slices below!

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For the matcha sponge:

1 large egg

26g granulated sugar

24g plain flour

2g matcha powder

18g margarine, melted

For the black sesame sponge:

2 large eggs

54g granulated sugar

48g plain flour

8g black sesame powder

32g margarine, melted

For the filling and topping:

40g margarine

85g icing sugar

½ tsp vanilla extract

25g icing sugar

Red food gel

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Preheat the oven to 170˚C. Lightly grease and line the base and the vertical sides of a Kaiser 25cm loaf tin with a single strip of baking parchment (see above for more details about the tin!).

Start by preparing the matcha sponge. Using an electric whisk, whisk together the eggs and granulated sugar until it reaches ribbon stage; this means you can lift the whisk out of the mixture and draw a figure of eight that sinks back into the mixture 2 or 3 seconds later.

Sift over the plain flour and matcha powder evenly over the surface of the mixture. Fold the dry ingredients in until it is just incorporated, scraping around the edge of the bowl and cutting through the centre, making sure all the flour is mixed in (it has a tendency to clump at the bottom).

Transfer some of the batter to a bowl with the melted margarine and use a spoon to quickly mix the two together until the margarine is incorporated. Pour back into the larger mixing bowl and fold to incorporate until even.

Pour into the lined loaf tin and give the tin a gentle tip to level out. The amount of batter looks like it won’t be enough but if you’ve done it correctly, the sponge should rise! Bake the matcha genoise for about 11 minutes until the edges are slightly golden brown and springs back when the surface is lightly pressed. Leave the cake to cool for 10 minutes before running a knife around the edge to loosen and transferring to a wire rack to cool completely. Trim the matcha sponge if it is uneven.

Repeat this procedure for the black sesame sponge, except the sponge will be thicker and will bake for around 17 minutes again until the surface is lightly golden brown and springs back to the touch. Once the black sesame sponge is completely cool, slice the sponge in half to give two sponges the same height as the matcha sponge. Set aside the black sesame sponge with the flat bottom to form the top of the angel slice.

For the buttercream, whip the margarine until slightly aerated. Add the icing sugar in two batches, mixing well between each batch. Add the vanilla extract and beat together until it forms a light smooth buttercream that is spreadable.

Spread half of the buttercream in an even layer over the surface of the other black sesame sponge, going right up to the edges. Place the matcha sponge on top and spread the rest of the buttercream evenly on the matcha sponge, again going right to the edges. Top with the set aside black sesame sponge, ensuring the base is on top so the top is level. Trim the edges to expose the layers. Place in the fridge while you make the icing.

Add enough water to the icing sugar (about 1 teaspoon) gradually to form a thick spreadable icing that doesn’t run. Remove 1 teaspoon of the icing and mix with red food colouring to give a pink icing. Place into a piping bag and cut off a medium sized hole.

Remove the cake from the fridge and use a sharp knife to divide the cake slab into 6 slices. Use a table knife to spread a layer of the white icing onto the top of 1 cake slice. Pipe horizontal lines of the pink icing across the white icing and use a toothpick to create a feather effect; drag the toothpick forwards and backwards through the icing, alternating the direction each time. Leave the icing to set before serving the cake slices.

 

Follow me on Facebook, Twitter and Instagram, subscribe to my YouTube channel and make sure to check out my other Bake Off Bake Along recipes:

• Biscuit Week: Rum and Raisin Chocolate Biscuit Bars
• Bread Week: Tangzhong Chinese Tear and Share Buns
• Dairy Week: Millionaire’s Coconut Ice Shortbread or Spiced Fig and Yoghurt Cake with Yoghurt Buttercream
• 1920s Week: Piña Colada Custard Tarts
• Dessert Week: Pistachio Matcha Layered Meringue Cake
• Festival Week: Sweet Potato and Taro Tangzhong Buns
• Pastry Week: Butternut Squash Pie
• Patisserie Week: Domed Princesstårta Tartlets
• Finals Week: Triple Layer Chocolate Drip Cake

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