Step 1

Preheat the oven to 160°C/fan140°C/gas Butter a 23cm springform cake tin, line the base with baking paper, butter again and dust all over with a little polenta. In a bowl, beat the softened butter and caster sugar together until light and fluffy, then gradually whisk in the eggs, one at a time.

Step 2

Fold in the polenta, almonds, baking powder and plain flour. Add the lemon zest and juice, and mix well. Spoon into the cake tin and smooth over using a palette knife.

Step 3

Bake for 1¼ hours until a skewer inserted into the centre comes out clean (cover the cake loosely with foil if it starts to colour too much).

Step 4

Meanwhile, make the syrup by heating the sugar, lemon juice and limoncello in a small pan.

Step 5

When the cake is ready, remove from the oven and pierce the top all over with a skewer. Spoon the warm syrup over the warm cake and leave to cool in the tin for 15 minutes. Carefully remove the cake from the tin and cool on a wire rack.

Step 6

Make the icing. Beat together the mascarpone, cream and icing sugar in a bowl until smooth. Place the cake on a serving plate and spread with the icing. Drizzle with the lemon curd, swirling it into the icing with the end of a skewer. Decorate with the toasted almonds.