Add the fruit purees into a small pan, and stir it over a medium heat until it reaches 40C/104F on a digital thermometer. Immediately tip in the sugar/pectin mixture and whisk this until it reaches a boil. Once boiling continue to cook for a further minute. 

Remove the pan from the heat and whisk in the fresh lemon juice. Pour the confit into a bowl and cover the surface with cling film. Allow it to chill in the fridge for 2 hours. 

Into a small saucepan, add the butter and melt this over a low heat. 

Meanwhile, sift the remaining dry ingredients into a medium bowl, add the egg whites, and whisk to combine. Pour in the melted butter and whisk until you have a smooth batter.

Split the batter into 4 separate bowls - I prefer to use more red/pink cake batter than green and white so I put slightly more batter in two of the bowls. Add the colouring to each bowl and stir until you have a bright vibrant colour. You can use gel food colour, but I used a fat-soluble colouring powder. 

At this point, you want to make sure you have a silicon mat (42x29.5cm), that fits snuggly into your sheet tray, as we are going to spread the coloured batter onto the silicon mat, chill it, then slot it perfectly into the sheet tray. You could try doing this on baking paper instead of a silicon mat but I haven't tested this. 

Take spoonfuls of the coloured batter and dollop it onto the silicon mat. Spread it out using a palette knife so you have a nice thin layer of the batter - you don't want this to be too thick. You will probably have some batter left over. 

Lift the silicon mat onto a half-sheet baking tray (45x32cm) and place it into the freezer while you make the cake batter.

Pre-heat the oven to 180C/355F Non-fan assisted. Into a stand mixer fitted with a whisk attachment, add the egg yolks, vanilla, lemon zest and the first part of sugar (60g). Whisk for 2-3 minutes on a medium speed until the mixture is thicker and pale in consistency. Set this mixture to one side. 

Into a stand mixer fitted with a whisk attachment, add the egg whites and whisk on a low speed until they become frothy with small bubbles. 

Increase the speed to medium and slowly add the sugar, a tablespoon at a time. Once you've added all the sugar, continue to whisk until you have a medium stiff peak.

Fold the egg whites in three parts into the thickened egg yolk mixture until it is homogenous.

Sift in the flour and whisk this through so there are no lumps, and finally pour in the wet ingredients and again whisk to combine. Ensure you really scrape the bottom of the bowl otherwise the oil will settle at the bottom and not incorporate properly. 

Remove the chilled coloured batter from the freezer, and pour the cake batter directly over the top, spreading it out evenly with a spatula. 

Place the tray into the oven and bake for 20 minutes, or until the sponge is an even golden colour all over. 

Remove it from the oven and allow it to cool for 5 minutes, before quickly & carefully flipping the tray over, onto another silicon mat. Peel off the silicon mat to reveal the coloured cake batter underneath. Allow it to cool for 15-30m.

Take the cooled sponge and cut it into 4 equal rectangular strips, trimming the edges so that you get a very neat rectangle. I prefer to use only 3 cake layers for the final cake, so pick your favourite 3! 

Remove the vanilla cremeux from the fridge, and whisk it in a stand mixer on a medium speed, just for 30s-1 minute, until it has thickened to a medium-stiff peak. Add this into a piping bag fitted with a large round tip piping nozzle. 

Place two of the sponges, coloured design facing down, onto a silicon mat. Take the chilled strawberry confit and spread and thin layer evenly across both sponges.

Remove the whipped strawberry ganache from the fridge and just briefly whisk it by hand to loosen it slightly. If it feels too loose, whisk it for longer to thicken it. Spread a thin layer of this on top of the strawberry confit.

Next, pipe even lines of the vanilla cremeux on top. 

Varey carefully stack the sponges on top of each other, then place the third sponge on top, with the coloured batter facing out. You should now have three sponges stacked on top of each other, with the coloured batter on the outside edges. 

At this point, it is good to chill it to help set the cream and give the cake some structure. You can do an hour in the fridge or 20-30 minutes in the freezer.

Once chilled, flip the cake onto its side, and lift it onto the serving plate. 

Add the vanilla whipped ganache into a stand mixer fitted with a whisk attachment and whisk until you have a medium stiff peak. This won't take too long around 1 minute or less, so keep an eye on the mixture so you don't overwhisk it. 

Add the mixture into a piping bag fitted with a small St Honore piping nozzle. 

Pipe diagonal lines across the top of the cake. 

Finish the cake by piping some more strawberry confit into the gaps of the whipped ganache and garnish with strawberries. Allow it to come to room temperature for 15 minutes before serving.