We won't be taking orders for this simply because we haven't got a spare 6 hours to squeeze this in and I really don't want to replicate the stress of the competition in the kitchen (we'll happily do any other type of rainbow cake)! But if you find yourself up for the challenge, and have a spare 6 hours (this thing can't be rushed...) then it's well worth doing to get all the WOWs. I really mean the WOW-WOW-WOWs.

 

Rainbow Charlotte Royale Recipe

• Cooking Time: Approximately 6 hours (includes baking and chilling times)
• Skill: Moderate to advanced skill level
• Servings: Depends on how you slice it, about 12 generous slices
• Calories: It's a decadent treat, so let's not count those! 500+per slice
• Nutritional Info: It's a dessert, so expect sugar, fats, and joy
• Allergens: Eggs, milk, and various other ingredients; check for individual sensitivities

Rainbow Sponge Layers

I doubled up the Rainbow Swiss Roll sponge recipe to make two sheets of swiss roll layers. 

INGREDIENTS

8 eggs (medium), separated into yolks and whites

40g caster sugar - first measure 

80ml milk

80ml oil (vegetable or any other neutral oil)

1 teaspoon vanilla extract

60g plain flour, sifted

60g corn flour, sifted

Salt, pinch

2/3 teaspoon cream of tartar 

120g caster sugar - second measure

Gel paste/liquid food colouring (the runny pastes are better for this recipe eg: Dr Oetker) in purple, blue, green, yellow, red and pink - 10 drops/1 tsp each

METHOD

1. Preheat the oven to 160 degrees celsius. Prepare 2 baking trays with parchment paper - cut the parchment to size with a spare inch on either side, crease along the base edges of the trays and cut out the corners so the parchment paper fits the trays well. Grease the trays with some butter or shortening and line the trays with the prepped parchment paper.

2. Whisk the egg yolks and the first measure of sugar, 40g, together till light in a mixing bowl. 

Add the milk, oil and vanilla in next and whisk till well combined. Tip in the flour and corn flour and gently whisk till mixed in and no visible lumps remain.

3. In a clean stand-mixer bowl with whisk attachment, break up the egg whites by whipping on medium speed till just frothy. Add in the salt and cream of tartar and whisk on high speed whilst gradually adding the second measure of sugar until you have a glossy meringue with stiff peaks.

4. Add half of the meringue to the wet batter and whisk gently to combine. Then fold in the remaining meringue using a rubber spatula. Be careful not to overmix or fold at this stage as you want to keep all that precious air in!

5. This is the part where you have to grab those extra bowls - you'll need 6 in total to divide the batter evenly into. Once you've divided them, put a teaspoon (or approx. 10-12 squeezes/drops) of yellow, green, blue, purple, pink and orange (mix of red and yellow) food colouring IN THAT ORDER into each bowl. This order is important because it will save your sanity in the next step.

6. With a rubber spatula, we are going to gently fold the food colouring into their batters in the following order:

• Yellow - gently fold to mix in the colour and scrape spatula against the lip of the bowl
• Green - using the scraped spatula, gently fold and scrape the spatula again when done
• Blue - repeat using the scraped spatula and scrape again when done
• Purple - repeat and scrape
• Pink - repeat and scrape
• Orange - repeat and scape

If you follow this order, you'll see there is minimal colour contamination between the batters and you're saving yourself a lot of washing up (or the need for 6 spatulas!)

7. Grab 3 disposable or reusable piping bags and pour the first three batters into each bag. Snip off 1cm at the tips and get ready to pipe into the prepared baking tin. This next step goes like in the speed of lightning.

8. Start with piping lines along the short side with one colour over a third of the tray. As the batter is light and fairly runny you will have to be light handed with the piping bags and have a steady pace. Don't worry if you have some wobbles, it's fine - if you have any big wobbles you can carefully scrape up the excess and spoon it back into the piping bag and carry on.

9. Repeat the piping with the two other colours, each a third of the tray, till you reach the end of the tray. You'll have quite a bit of batter left - pipe the remaining batter evenly over their respective segments on the tray. Once the bags are emptied, give them a quick rinse and fill up with the remaining three colours and repeat on the second tray in a similar fashion.

 

10. Tap the baking trays against the surface a few times to let any air bubbles escape and then bake in the oven for 15-20 minutes or until the sponges start to brown on the surface and is springy to touch. 

11. Once baked, retrieve from the oven using oven mitts or a tea towel and place the trays on a heat resistant surface. Cut another few pieces of parchment paper to size and place over a wire rack. Place the lined wire rack upside down over the baking tray and flip over to release the sponges one by one. Peel back the parchment paper on the bases of the sponges immediately and remove it from the other side too so the sponges starts cooling on the wire rack. This step is important so you don't have discolourations on the sponges from trapped moisture.

12. Once the sponges are cool, which won't be long as they are fairly thin, trim the edges and cut along the colours using a razor sharp cake knife to have 6 layers of rainbow sponge!

 

Cream Cheese Ganache Frosting

INGREDIENTS

300g double cream

300g white chocolate, chips or cut into small chunks

450g full fat cream cheese

METHODB

Boil the double cream in a saucepan and pour over the white chocolate chips in a mixing bowl. Use a hand held mixer with whisk attachment to blend until the ganache comes together and cover with cling film (in contact with the ganache) and chill in the fridge. In another mixing bowl, place the chilled cream cheese and blend with hand held mixer with the whisk attachment till fluffy.

Use a spatula to scrape all the whipped cream cheese into the chilled ganache and whip till firm and light. It's bloody delicious, don't spoon it all into your mouth!

Raspberry Bavarois

INGREDIENTS

4 leaves of gelatin

150g pureed raspberries (you'll need about 200-250g of fresh raspberries to blend and sieve out the seeds to get the net weight of puree needed)

300ml whole milk

4 egg yolks

50g caster sugar

200ml whipped cream

METHOD

1. Soak the gelatine leaves in cold water until soft. 
2. Pour the milk into a pan and heat over medium heat until simmering. Whisk the egg yolks and caster sugar together in a mixing bowl until pale and thick. Pour the hot milk over the eggs and whisk together.
3. Drain the gelatine, squeezing out excess water and add it to the custard. Pour the custard back into the pan and cook until it coats the back of a spoon. Be super careful not to boil or have it bubble - it'll split and break down the gelatin otherwise. Transfer to a clean bowl and leave to cool slightly before folding in the raspberry purée. Cover with cling film making sure it is in contact with the surface of the bavarois and let chill in the fridge for 30 minutes.

Whilst the filling is chilling...we'll crack on with the Charlotte Royale sponge layers!

Assembly of the Rainbow Charlotte Royale

METHOD

1. Spread the cream cheese ganache over the coloured sponges with a palette knife and stack/sandwich them into two - 1 sandwich with purple, blue and green layers, and the other with yellow, orange and pink layers. Let them chill in the fridge till the cream cheese ganache firms up.

2. Using a tall hot beaker of boiling water, warm the razor-sharp cake knife in the water and dry off on a towel before trimming the edges of the stacked sandwiches. Make sure to clean and dry the knife between each cut. Portion each trimmed stack into 2 inch wide portions along the long side to get 'finger sandwiches'. Then slice each 'finger sandwich' into 1/4 inch thick squares.

3. Line a 2 litre bowl (like a Pyrex one) with cling film. Place a sponge layer square in the middle, and then place alternating squares in a weave pattern around the central square, neat side down. It's a bit like Tetris, as you then have to start filling in the gaps with the sponge layer squares. once you've built it up to the top (don't worry if you've made a gaff here or there...it'll be barely noticeable, just follow a pattern as you go along), cover with cling film and chill for 15 minutes till its firm. Reserve the remaining squares (this will be the base).

4. Remove the cling film and using a paring knife, trim a straight edge along the rim to tidy. Spread a nice thick layer of cream cheese ganache all over the inside and chill for another 15 minutes. Once it's firm to the touch, pour in the bavarois until 1/4 inch below the rim of the sponge line.

Place in the fridge to chill for 30 minutes. Once chilled, spread another layer of cream cheese ganache and place the remaining sponge squares over the top and cover with cling film and let chill in the fridge ideally overnight, or at least 4 hours to set properly (if it's not chilled enough it risks falling apart when demoulding and your life will be ruined).

5. Once the Charlotte Royale has chilled, tip the bowl over a 12" cake drum, cake stand, or if you want to be fancy and make life easier simultaneously like me, a marble lazy susan/turntable. Slowly remove the bowl and peel off the cling film from the Rainbow Charlotte Royale.  

Decorating the Rainbow Charlotte Royale

Neutral Glaze

75g caster sugar

125g water

1 tbsp ground arrowroot/tapioca starch 

METHOD

1. Place the caster sugar and water in a small saucepan over medium heat and bring to a simmer. Dissolve the ground arrowroot powder in 2 tablespoons of water and pour into the simmering sugar syrup and bring to a simmer again. Remove from the heat and let it cool slightly before spooning it over the Rainbow Charlotte Royale. Clean off any drips on the board with a damp cloth. Using a piping bag fitted with a savoy nozzle of your choice (I always reach for this handy set of Jem nozzles) pipe swirls or dollops of cream cheese frosting around the base to finish.

I told you, this dessert is TIME gobbling. You can however make a bulk of the elements in advance - the sponges can be baked, trimmed and chilled for a few days wrapped in cling film, the cream cheese ganache frosting can also be made a few days in advance and re-whipped before use, the sponge sandwich fingers could be assembled and used to line the bowl a good few days in advance with just the bavarois being made and filled into the lined bowl the night before or on the day. It's so fun to look at, tastes delightful and if you're not actually making it in a stressful competition, it is a joy to make.

If you take on this project, please share your creation with me over on instagram by tagging @angesdesucre #angesdesucre - I'd love to ogle! If you have any questions, pop them in the comments below and I'll get back to you :)

Happy Rainbow Royale raving,

Reshmi xoxo