BBC Food - Recipes - Almond and lemon polenta cake with orange mascarpone

Ingredients

• 225g/8oz unsalted butter
• 225g/8oz caster sugar
• 3 free-range eggs , beaten
• 225g/8oz ground almonds
• 115g/4oz instant polenta
• 1 tsp baking powder (gluten-free if necessary)
• 3 lemons , zest and juice only
• icing sugar , for dusting
• 2 lemons , juice only
• 3 tbsp caster sugar
• 250g/9oz mascarpone
• 2 oranges , zest only, plus splash of juice
• 50-75g/1¾-2½oz icing sugar , sieved
• 75-100g/3-4oz caster sugar , for dusting
• 100ml/3½fl oz orange juice
• 4 satsumas , peeled and cut in half horizontally