Heat oven to 170°C/150°C fan forced

Prepare the tin by lightly greasing it.In one bowl whisk egg whites. Once they start increasing in volume, start adding 2 tablespoons of the caster sugar (one at a time) and continue to beat until you get a loose meringue style mix.In another bowl beat the egg yolks with the remaining sugar until pale and creamy. Do not allow sugar to sit on egg yolks without being whisked. Add the oil and ricotta and mix until combined.Gently fold in the self-raising flour and the almond meal, the cinnamon, the orange zest and juice and vanilla.Gently fold in the egg whites.Pour cake batter into prepared tin.Bake in the oven for 35 to 40 minutes (or until a skewer comes out clean).Allow to cool before attempting un-mould the cake.Dust with icing sugar and pile oranges onto central ring of the cake.