Start by lining three 8inch round cake tins (sandwich or deep - use whichever you have) with silicone liners or baking parchment and preheating the oven to 170˚C. 

Whisk the eggs and caster sugar together on high speed until tripled if not quadrupled in volume. Dribble in the lemon juice with the whisk still running.

Sift over the flour and almonds and fold in. Divide between the three cake tins and bake for approximately 12 minutes. They will be quite pale but dry to the touch and bouncy when pressed in their centres when done. 

Cool still in the tins on a rack for 5 minutes then remove from the tins to finish cooling which shouldn't take much more than another 15 minutes.

In a small bowl, add the lemon juice and still in the gelatine. Allow to stand until "bloomed" - i.e. it because a firm gel. Either heat on in a small saucepan until melted or give 15 second zaps in the microwave (on medium heat). Allow to cool whilst you prep the rest.

Still the double cream and icing sugar together then add in the cream cheese and lemon curd (add the food colouring now if using). Whisk on high (I use my stand mixer but an electric hand whisk would do) until it starts approaching firm peaks - it won't get stiff and over-whipped like when you whip cream by itself can. 

Pour in the melted but cooled gelatine and stir well - it will look runny at this point and you will be worried if it will set. Don't be! Simply whisk again until those almost stiff peaks form. Gelatine whisks up really well so it plus the cream should leave you with a super light and fluffy mousse. 

If you have a springform 8 inch cake tin, line it with silicone liners or fresh parchment and place one of the cooked sponges in the bottom. If not, make a 3-4 inch deep collar of parchment and secure it around the first layer of cake (I use a piece of sellotape on the outside of the parchment). This is a job to do with a helper if you can! 

Scoop the mousse into a large piping bag if you have one and pipe half of it on top of the sponge - if not, spoon it in and smooth with a spatula. 

Add the second sponge layer, the second half of the mousse and top with the final sponge. Press lightly to level and ensure there are no air pockets then chill overnight in the fridge. 

Remove the cake from the fridge and if using a cake tin to set it in, unclip and remove it to a serving plate. Carefully peel away the silicone liner or parchment and if needed, tidy up the edges with a hot palette knife. You shouldn't need to do much tidying up!

Sift over the icing sugar to give a reasonably thick layer. Add 1-2 tbsp of the lemon to a small piping bag or a plastic food bag and snip off a small corner - pipe lines of curd over the top of the cake. Tip - be brave and go fast or the heat of your hand will start to melt it and make it harder to pipe. 

Whisk the double cream to just soft peaks then fold in remaining lemon curd until just rippled. Put a star tip into a piping bag and add the fool - pipe tall rosettes close together around the edge of the cake and finish with candied lemon, pineapple or even just some curls of lemon zest to decorate.

Keep chilled until serving and use within 48 hours.