- 225g/8oz butter, plus extra for greasing
- 350g/12¼oz caster sugar
- 250g/9oz mashed potato
- 250g/9oz ricotta
- 4 free-range eggs
- 125g/4½oz flour
- 1 tsp baking powder
- 2 lemons, juice and grated zest
- pinch ground cinnamon
- 1 tbsp poppy seeds
- crème fraîche, to serve
- Preheat the oven to 180C/350F/Gas 5. Grease a 24-26cm/9-10in loose-bottomed cake tin with butter.
- Cream the butter and sugar together in a bowl until pale and fluffy.
- Whisk in the mashed potato and ricotta using an electric whisk for 4-5 minutes, or until very fluffy.
- Crack in the eggs, one at a time, and whisk again until fully incorporated into the mixture.
- Sift the flour and baking powder together, then fold the mixture into the cake batter until well combined.
- Fold in the lemon juice, lemon zest, cinnamon and poppy seeds until well combined.
- Spoon the cake batter into the prepared cake tin. Bake for 1-1¼ hours, checking regularly, until a skewer inserted into the centre of the cake comes out clean. (If the top of the cake starts to darken too much during cooking, cover it loosely with aluminium foil.)
- Set the cake aside to cool slightly, then serve with crème fraîche.