This is a bit tricky but well worth the effort, It's moist and tangy, with just a hint of fruity olive oil. To be extra fancy serve this with a drizzle of chocolate sauce.
Preheat your oven to 180C. Grease and line the base and side of a 22cm cake tin
Reserve 2 tablespoons of sugar. Use an electric beater or mixer with the balloon whisk attachment to beat egg yolks, mandarin rind and remaining sugar in a bowl until doubled and a ribbon trail forms when the beater is lifted.
Combine your olive oil and orange juice in a jug. Mix the flour and ground almonds in a small bowl. In alternating batches, add the olive oil mixture, in a slow, steady stream, and the flour mixture to the egg yolk mixture, beating constantly on a low speed until just combined.
Use a clean electric beater to beat egg whites and reserved sugar in a large clean, dry bowl until firm peaks form. Use a large metal spoon to fold in the egg whites into the flour mixture until just combined.
Pour into the prepared pan. Bake for 35-40 minutes or until golden and a skewer inserted into the centre of the cake comes out clean. Cool the cake in the pan for 10 minutes. Transfer to a wire rack to cool completely. Dust with icing sugar.