Preheat oven to 170°C. Grease and line base and sides of a 22cm round cake pan with non-stick baking paper.

Use an electric mixer to beat butter, sugar, orange rind and vanilla extract for 10-12 minutes, occasionally scraping down the side of the bowl, until pale and creamy. Add eggs one at a time, beating well between each addition.

Combine polenta, flour and almond meal in a bowl. Add half to the butter mixture along with half of the orange juice. Mix until well combined. Repeat with the remaining polenta mixture and orange juice.

Pour into prepared pan. Smooth the surface. Bake for 40-50 minutes or until a skewer inserted into the centre comes out just clean.

Set cake aside in the pan for 15 minutes before turning out onto a wire rack to cool. Serve dusted with icing sugar.