INSTRUCTIONS

1. Preheat oven to 160 degrees Celsius or 320 degrees fahrenheit.
2. Whip the butter in a mixing bowl on high speed for at least two minutes.
3. Add the sugar and continue to whip until a soft cream forms.
4. Add the following to the mixing bowl, one at a time, and blend after each; eggs (one at a time), salt, grated lemon zest.
5. Alternate adding and blending the flour, baking powder, hazelnuts and milk into the mixing bowl.
6. Continue to mix the ingredients on medium speed until the texture of the batter has a light and airy consistency (similar to mousse).
7. (Note: Do not beat the batter for too long after adding the baking powder.)
8. Coat the surface of the fluted pan with butter before dusting it with flour, then shake off any excess flour before adding the cake batter to the pan.
9. Pour the batter into your greased and floured pan.
10. Bake the cake in the pre-heated oven for 45 minutes. While the cake is baking prepare your lemonade mixture by first squeezing the lemons into a pitcher or other container from which you can easily pour the mixture later.
11. Add the sugar to the lemon juice, and mix until the sugar is fully dissolved in the lemon juice.
12. Add the water and mix well.
13. Once the cake has finished baking, let it sit for two hours outside the oven to bring it to room temperature.
14. Slowly pour a little bit of the lemonade mixture all over the cake in the pan every 10 minutes (three times total) for 39 minutes to allow the cake to absorb the lemonade mixture very slowly.
15. After the first 30 minutes, tip the cake onto a serving platter and add the remaining lemonade to the top of the cake, distributing it evenly all over the cake.