Torta Paradiso

Method

1. Preheat the oven to 190°C (static oven).
2. In a large bowl, beat the softened butter with half the sugar and the seeds from the vanilla bean until creamy and light, about 7-8 minutes.
3. Grate the lemon zest into the mixture and beat to combine.
4. Add the eggs one at a time, mixing well after each addition until fully absorbed.
5. Add a pinch of salt.
6. Sift together the flour, potato starch (or cornstarch), and the optional baking powder.
7. Fold the dry ingredients into the butter mixture in three or four additions, using a spatula and folding from bottom to top until just incorporated. Do not overmix.
8. Butter and flour a 22-24 cm round cake pan.
9. Pour the batter into the prepared pan and smooth the top.
10. Bake at 170°C (reduce the oven temperature after placing the cake) for 35-40 minutes, until a skewer inserted in the center comes out clean and the edges pull away from the pan. If the top colours too quickly, cover with aluminum foil for the last 5 minutes.
11. Let the cake cool in the pan for 10 minutes.
12. Turn out onto a wire rack and let cool completely.
13. Dust with powdered sugar before serving.