Coconut and lime angel cake

Method

1. Heat the oven to 180°C/160°C fan/gas 4. Sift the flour and 100g of the caster sugar into a bowl and set aside.
2. Whisk the egg whites in a large bowl with an electric mixer on medium for 1 minute or until frothy. Add the lime zest, juice, cream of tartar and salt. Whisk for 2-3 minutes until the mixture forms soft peaks when the whisk is raised. Increase the speed to high, then add the remaining caster sugar, a little at a time, until the mixture is glossy.
3. Sift a third of the flour/sugar mixture over the egg mix and fold gently with a metal spoon or balloon whisk to just combine. Repeat with the remaining two thirds, folding as gently as possible.
4. Carefully transfer the batter to the cake pan, then run through it with a knife to remove any air pockets. Bake in the middle of the oven for 45-50 minutes until risen, golden and springy.
5. Take out of the oven and immediately place upside-down on the pan’s cooling legs. Leave to cool for 1 hour 30 minutes (we know this seems odd, but trust us!). Run a knife around the cake’s inner and outer edges, then push the cake out, still attached to the pan base, onto a wire rack. Using a palette knife, carefully lift away the pan base. Cool.
6. To make the icing, whisk the cream, icing sugar, lime juice, coconut cream and rum in a large mixing bowl with a balloon whisk or electric mixer. Stop once the mixture develops soft, pillowy peaks. Spread the icing all over the cake to cover, then scatter with a generous amount of coconut flakes. Use a serrated knife to slice the cake. It’s best eaten the day it’s baked.