For the sponge
360g caster sugar
360g baking margarine
360g self-raising flour
pinch of salt
1-2 tsp Orange extract
1. Preheat the oven to 175 C fan.
2. Grease and line 2 8 inch cake pans.
3. Beat the sugar and margarine together, until light and fluffy.
4. Add the orange extract, zest, 2 eggs and a bit of the flour. Mix on high until the eggs are incorporated, then repeat adding the remaining eggs 2 at a time.
5. Add the remaining flour, mix on low until the mix is just coming together, then finish the mix by hand.
6. Divide the mixture equally between 2 pans and bake in the centre of the oven for 15 - 20 mins.
For the Buttercream
4 egg whites (you could use the yolks to make orange curd!)
300g caster sugar
400g butter (room temperature)
1 - 2 tsp orange blossom water
1. Place the egg white and sugar together in the bowl for your stand mixer.
2. Put the bowl over a saucepan of simmering water and heat gently, stirring until the sugar is completely dissolved and the temperature if at least 60 C. Rub the mix between your fingers, when you can't feel any sugar, it's ready for the mixer.
3. Turn the mixer to high and whisk the egg mixture until it is completely cool, this can take 10-15 mins.
4. Once cool start to add the butter a little at a time, it will look a bit strange right up until the end, but stick with it.
5. Flavour the buttercream with the orange blossom water, to taste.
For the candied orange slices
1 cup of caster sugar
1 cup of water
1 orange sliced (discard the end)
1. Bring the water to a boil, add the slices of orange and cook on high for 2 mins, flipping halfway through.
2. Remove the slices from the water.
3. Stir the sugar into the water and bring the boil, add the slices of orange and reduce the heat to low.
4. Simmer for 1hr 15mins, turning the slice every 15 mins.
5. Remove the slice and allow to dry on a cooling rack.