Grease and line three deep 6 inch cake tins and set aside.

Sieve the flour into a bowl. Add the salt and baking powder, mix evenly and then set aside.

In a large room temperature bowl, whisk the eggs until the yolks and whites have mixed.

Add the sugar gradually to the eggs while whisking (I used a large spoon and added every few seconds). If using a standing mixer with the whisk attachment, proceed to the next step whilst the eggs and sugar are doing their thing until very pale and tripled in volume. If using an electric hand whisk (as I did), stay with your eggs and sugar and whisk until very pale and the amount has tripled in volume. It’ll take a bit of time but it’s worth the wait.

In a microwave safe bowl or jug, melt the butter in with the milk and heat the mixture. Do this in bursts of 1 minute until the mixture is hot to touch. Do not let it boil (a bit of frothing is fine).

Sprinkle the flour mix, ⅓ at a time over your whisked sugar and eggs and whisk. When you can no longer see any flour, stop whisking.

Add the vanilla and oil to the hot milk and butter mix and whisk.

With your milk and butter mix still hot, add two rough ladles of your combined flour and egg mix into the milk and butter. Whisk until smooth.

Pour the milk and butter mix over the rest of the flour and egg mix ⅓ at a time and whisk in between. Whisk completely until the batter is pourable.

Ladle into the cake tins – I do two ladles per tin and continue this until the batter is used up. This provides even amounts.

Add the red food colouring into the first tin, the yellow food colouring into the second tin and the blue food colouring into the last tin. Whisk each one gently just until the colour is combined (this way you keep the air in the batter!). Make sure to rinse your whisk in between each tin so you don’t mix colours.

Tap each tin 3 times on the counter to knock out the large bubbles.

Once baked, leave to cool in the tins for 15 minutes, then turn out upside down onto a cooling rack to cool completely.

Whilst the cakes are cooling, make the buttercream.

Beat the butter until softened and add the sugar bit by bit, beating in between.

Blitz your Oreos in a food processor until they become a fine crumb. Alternatively, crush them in a bag with a rolling pin.

Add the Oreos and the cocoa powder to the buttercream. Add milk 1 tbsp at a time to loosen the buttercream. It needs to be soft enough to not break the sponges (which will be very soft!).

Melt the dark chocolate in the microwave in bursts of 20 seconds. Add to the buttercream and beat until smooth.

Break off some modelling chocolate and knead it until pliable. Roll out into a large circle. Using a stencil or by eye, cut out a Triskelion. Take your time and have fun with this!

Break off another piece of modelling chocolate and roll it out with your hand into a long and thin sausage – long enough to go around the diameter of your cake. Use a rolling pin to flatten it out so that it looks like a belt. Use a knife to slice off the edges and ends to make them sharper.

Scrape some buttercream onto your cake stand/board/plate and place the first blue layer. Smooth buttercream over the top and layer the first yellow one on top of it. Add more buttercream. Using a round cookie cutter, cut out a hole of the centre of the first red layer and then add it to the cake. Add more buttercream.

Cut a hole from the centre of the second blue layer and add to the cake. Separate the yellow and green M’n’Ms from the rest and pour them into the hole. Continue adding buttercream and the last layers until you have layered all of your cakes.

Smooth buttercream over the entire cake in a thin layer to create a crumb coat.

Chill in the fridge for a few minutes.

Add more buttercream over your crumb coat and smooth with a palette knife. Make it as smooth or rough as you like, but rough will look more like aged wood.

Place your modelling chocolate Triskelion and lid collar on your cake, using the buttercream as a glue.

Chill again until set.