To make the sponge layer cake, line and lightly grease a 22cm baking tin. Preheat oven to 190 ºC.
Whisk eggs, optima flour, water and vanilla essence in an electric mixer until thick and fluffy. Mix in melted butter and colouring. Pour batter into prepared tin.
Bake in preheated oven till golden brown and cooked. Leave cake in the tin to cool slightly before turning out onto a wire rack to cool completely. Wash tin for later use.
To make the jelly coffee layer, combine all the ingredients together and bring to a boil until the sugar and agar-agar are completely dissolved. Pour mixture into the baking tin and set aside.
To make the kaya layer, mix the ingredients together in a saucepan and bring to a low boil until mixture thickens. Pour kaya mixture over the semi-set coffee layer. Top up with the cooled sponge layer.
Press down the cake slightly. Chill before cutting into neat slices to serve.