Instructions

1. Preheat oven to 180°C/160°C fan/gas 4. Grease 4 20cm (8inch) round cake tins and line the bottom of each with parchment paper.
2. Whisk together the eggs white, milk and vanilla then set aside.
3. Combine the remaining ingredients in a large bowl and use an electric mixer to mix until the butter has mostly been broken up and the mixture resembles breadcrumbs.
4. Add half of the egg white mixture and mix until combined, scraping down the sides of the bowl as needed. Add the remaining egg white mixture and mix again until batter is smooth.
5. Divide batter equally between 4 bowls. Colour each with either green, blue, yellow or red gel food colouring. It’s best to add just a small bit at a time, mixing in between until you get the desired shade.
6. Pour each coloured batter into the prepared cake tins and bake for 25-30 minutes, or until a toothpick inserted in the centre of the cake comes out clean.
7. Leave to cool in baking tins on a wire rack for about 10-15 minutes before carefully turning out and leave to cool completely. Peel away parchment paper once cold.
8. For the buttercream frosting, in a large bowl, beat butter with an electric mixer until smooth. Add icing sugar, milk, vanilla and salt. Start beating together with the mixer on lowest speed, once icing sugar has been mixed in, increase speed and beat until frosting is smooth and creamy. Make sure to scrape down the sides of the bowl so that everything is well incorporated.
9. When ready to assemble, place one of the sponges on a cake plate or serving dish. Spread about 1/3 cup (80ml) buttercream over the top of the sponge, then gently place the second sponge on top, gently pressing down to make sure it’s sitting properly and is level. Repeat until you place the final sponge on top, but do not frost the top.
10. Colour the remaining buttercream with the yellow gel colouring, adding a small bit at a time, checking the colour between mixing, until you reach the desired shade.
11. Coat the entire cake with a crumb coating of buttercream, which is just a very thin layer of buttercream used to trap any stray crumbs. Place cake in the fridge and allow crumb coat to firm up, about 15-20 minutes. Once crumb coat is set, remove from the fridge. Give the remaining buttercream a quick mix with a spatula, then finish icing the cake with a thick layer of the frosting. Return cake to the fridge to firm the frosting.
12. To make the chocolate topping, heat cream in a small pot until it starts to bubble up around the edges. Pour cream over the chocolate in a heat resistant bowl, then slowly stir until the chocolate has completely melted and the mixture is smooth. Add the syrup and stir to combine. Place in the fridge so that it can thicken slightly. About 20-30 minutes. The consistency needs to be slightly thicker than syrup.
13. To decorate the cake, pour chocolate mixture on top of the cake, starting around the edges, and use a spatula to gently spread it over the top. Leave the chocolate to naturally drip down the sides. Place in the fridge and chill for about 30 minutes to help the chocolate firm up, then decorate the top with mini eggs.
14. Can be kept at room temperature if cool, otherwise, keep in the fridge but remove about an hour before serving. Will keep for 3-4 days and it’s best to keep the cake covered to avoid it drying out.