1.Preheat oven to 150°C (130°C fan forced).
2.Make lemon compote. Cut lemon slices into quarters, remove seeds. Layer quarters in a medium non-metalic baking dish. Place sugar, rosemary and the water in a small saucepan, stir over a low heat until sugar is dissolved. Bring to the boil. Reduce heat, simmer 1 minute. Pour syrup over lemon quarters. Cover surface of lemon mixture with baking paper, then cover the dish with foil. Bake 30 minutes. Remove foil and paper, bake a further 30 minutes or until syrup is thick and lemons are caramelised. Cool.
3.Increase oven to 180°C (160°C fan forced). Grease a 20cm (8-inch) round cake pan, line base and side with baking paper.
4.Beat butter and sugar in a small bowl with an electric mixer until pale and creamy. Beat in eggs, one at a time. Stir in ground almonds, polenta and baking powder, then stir in rind, juice and orange blossom water. Spread mixture into pan, smooth the surface.
5.Bake cake 1 hour or until a skewer inserted in the centre comes out clean. Cool cake in pan.
6.Serve cake topped with lemon compote.
Orange blossom water, also called orange flower water, is a concentrated flavouring made from orange blossoms. It is available from Middle Eastern food stores, delicatessens and some supermarkets.Note