Mix oil and zest together in a small bowl and set aside.
Using a stand mixer whisk egg whites and cream of tartar in a large bowl until stiff peaks form. Gradually add ½ cup of the caster sugar, continue to whisk until mixture is stiff and glossy. Set bowl aside.
In a separate bowl beat egg yolks and oil & zest mixture until pale yellow. Then mix in milk and juice.
Sift in flour and baking powder, and then add sugar and salt. Continue beating until well combined at a medium speed.
Remove bowl from stand mixer and fold through ⅓ egg white mixture. Once incorporated gently fold through remaining egg white mixture until just combined. Don’t over mix.
Pour batter into an ungreased angel food cake pan. Place in the oven and bake for 50 minutes.
After 50 minutes turn up the heat of the oven to 180°C (350°F) for an additional 15 minutes. The cake is cooked when you gently press it in the middle with a finger and it springs back. Cooking Tip: Don’t open the oven door for the first 45 minutes of cooking to ensure the cake rises.
Once out of the oven turn cake tin over and allow to cool completely upside down.
Once cool turn cake pan back over and run a sharp thin knife around the outside edges of the tin and then around the central tube. From underneath gently push the cake out from the bottom, it will still be attached to the removable base. Once removed from the tin, gently remove cake from the base again using the sharp knife.
The top of the cake when cooking becomes the base of your cake for decorating and serving. This is how you get that perfectly flat top. If your cake hasn’t risen evenly, you may wish to trim it slightly so it sits level.
To make icing: Sift icing sugar into a medium bowl and add blood orange juice a bit at a time, mixing as you go until the icing reaches the consistency of runny honey.
Drizzle icing over the top of the cake and decorate with fairy floss and flowers.
You will need at 23 cm (9 ¼ inch) angel food cake tin with extended feet and a removable base for this recipe.If you don’t have a chiffon tin/angel food tin with extended legs, don’t panic. Place the tin upside down over a bottle. You stick the neck of the bottle in the hole in the centre of the cake tin.Do not grease or line your tin