To prepare the sponge cake:Beat the eggs, sugar, lemon zest and vanilla for 5 to 6 minutes until foaming; add the flour gradually using a spoon and mix slowly.
Pour the mixture into a greased 15cm heart shaped baking tin and bake in a preheated oven at 180 °C for 20 to 25 minutes, or until a skewer inserted in the middle comes out clean.
To prepare the cream:
In a mixing bowl, mix well the remaining 200ml water with the corn flour, egg yolk and vanilla, and then pour them into the boiled mixture and bring to a boil again, with constant stirring, until the mixture thickens. Set aside to cool. (Cover with cling film to prevent the top from drying up.)
Beat the cold custard cream using an electric mixer until soft and smooth.
Using a big spoon, add 300g of the whipped cream and mix slowly.
To prepare the sugar syrup:Bring the water and sugar to a boil, and keep aside to cool down.
Add the vanilla essence before use. Use the syrup cold.
Finally:Cut the sponge into 3 layers; put 1 layer on a wooden or carton base. Brush the layer with sugar syrup, and using a spatula, spread evenly half the quantity of the cream on it, and then add half the sliced strawberry; put the second layer over and repeat the same process. Place the last sponge layer on top and keep the cake in the fridge for at least 1 hour.
Mask the cake with the remaining 350g whipped cream and with your hand stick the crushed coconut on the sides of the cake only.
Cut the whole strawberries into halves (keeping some with the green leaves) and arrange on the top of the cake and around it. Put the cake in the fridge.
Warm up the strawberry jam and spread it slowly over the strawberries using a brush.