Preheat oven to 180˚C (160°C fan forced). Lightly grease and line the base and sides of a 23 X 12 x 7cm loaf pan with baking paper.
Beat butter and sugar with an electric mixer on high until pale. Add eggs, one at a time, beating well after each addition, then fold in vanilla. Combine almond meal, polenta, turmeric and baking powder together in a bowl, then fold into butter mixture. Add lemon zest and juice and stir to combine well.
Spoon the batter into prepared pan and use the back of a spoon to smooth the top. Sprinkle almonds over the surface and bake for 1 hour or until golden and a skewer inserted into the centre comes out clean. Stand in pan for 1 hour to cool, then lift cake onto a cooling rack, and allow to cool completely.
For baked fruit: Toss rhubarb, strawberries, sugar and cinnamon together in a bowl to coat. Spoon the fruit mixture evenly over the base of a baking paper-lined baking tray, cover lightly with a sheet of foil, and bake in the oven at 160˚C until the rhubarb is tender – about 10 -15 minutes. Allow to cool.
Place the yoghurt and cream in a bowl and beat to stiff peaks. Serve the cake with baked fruit, yoghurt cream and a sprinkle of icing sugar.