To prepare the sugar syrup:Bring the water and sugar to boil, and then keep aside to cool down. Add the vanilla essence before use. Use cold.
To prepare the sponge cake:Beat, using electrical mixer, half the quantity of the eggs, sugar, lemon zest and vanilla for 8 to 10 minutes until foaming. Using a spoon, add half the flour gradually and mix slowly.
Pour the mixture into a greased 27x27cm baking tin, and bake in a preheated oven at 180 °C for 25 to 30 minutes, or until a skewer inserted in the middle comes out clean.
Repeat steps 2 and 3 again using the other half of the sponge cake ingredients to make another sponge.
To prepare the cream:
In a mixing bowl, mix well the rest of the water with the corn flour, egg yolk, lemon zest and vanilla, and then pour them into the boiled mixture with constant stirring. Bring to boil with constant stirring until the mixture thickens. Set it aside to cool. (Cover with cling film to prevent the top from drying up).
Using an electrical mixer, mix well the custard cream (should not be cold, but warm or at room temperature). Add the soft butter and mix for 5 to 8 minutes. If the cream looks crumbled, you can reheat it using hot water bain-marie or on direct fire to allow the butter to mix well with the custard.
To prepare the almond paste:Combine the almond powder, icing sugar, NESTLÉ Sweetened Condensed Milk, vanilla essence, corn flour and water; mix slowly making soft dough with your hand (avoid over-mixing the dough). If the almond paste is still dry, add a little amount of water as the quality of the almond might be old or dry. Cover with cling film and keep aside.
Finally:Cut each sponge into 2 layers; put 1 layer on a wooden or carton base. Brush the sponge with sugar syrup and, using a spatula, spread evenly the cream on it.
Add some of the banana slices, and then the second sponge layer. Repeat the same layering process until you add the last sponge layer. Keep in the fridge for at least 1 hour. (Keep some of the cream to cover the cake.)
Cover the cake with a thin layer of the cream. Sheet the almond dough using a wooden roller with corn flour or icing sugar (2mm thickness); cover the top of the cake.
To cover the sides, cut the rest of the almond dough into 4 rectangular pieces to fit, and stick one piece on each side.
Take the rest of the almond paste and color it with the black food coloring (you can use any other color). Make 4 equal balls (oval shape) and put them on the 4 corners of the cake.
Use 12 straws to connect the almond balls, thus forming a boxing ring.
Put the Bratz doll in the middle of the cake, and with the remaining cream pipe the side and the top of the cake.