Pre-heat the oven to 160 degrees Celsius or 320 degrees Fahrenheit. Whip the butter in a mixing bowl on high speed for at least two minutes.
Add the sugar and continue to whip until a soft cream forms. Mix the baking powder into the flour and set aside.
Add the following ingredients to the mixing bowl, one at a time, and blend after each
: Eggs, one at a time,
salt, grated lemon zest
Alternate adding and blending the following ingredients into the mixing bowl:
Flour and baking powder mixture and milk. In other words, add one quarter of the flour and blend; then, add one quarter of the milk and blend. Repeat this process until all of the flour and milk are blended into the batter.
Mix the ingredients on medium speed for about five minutes until the texture of the batter has a light and airy consistency (similar to a mousse). NOTE: Do not beat the batter for longer than five minutes after adding the baking powder. Coat the surface of the fluted pan with butter before dusting it with flour. Shake off any excess flour before adding your cake batter to the pan. NOTE: This step creates a non-stick surface so that the cake will easily release from the pan and retain its shape.
Pour the batter into your greased and floured pan.
Bake the cake in the pre-heated oven for forty minutes. Note: Do not open the oven while the cake is baking or it will not rise properly.
While the cake is baking in the oven, prepare the lemonade mixture as follows.Squeeze the lemons into a pitcher (or other container from which you can easily pour the lemonade mixture later). Add the sugar to the lemon juice.
Mix until the sugar is fully dissolved in the lemon juice. Add the water.
Once the lemon cake is finished baking, let it sit for two hours outside the oven to bring it to room temperature.
Before we start this process, we want to ensure that the cake does NOT stick to the pan. In getting it to room temperature, the butter has solidified and that means there is a risk that the cake will stick to the pan. Here is the process just to ensure it does NOT stick to the pan before we proceed.
Place a plate on top of the pan. Tip the pan over and carefully shake the cake out of the pan. Immediately, place the cake pan back onto the cake. Carefully turn the pan back over. Remove the plate to expose the cake. This will seem like we have done nothing, but what we have done is to ensure that the cake will not stick later when we are ready to plate it.
NOTE: If the cake does seem like it wants to stick, you will need to place the cake back in the oven for a few minutes, just to warm the butter, and it will release from the pan easily.
Now it is time to add the lemonade mixture to the cake – that is what makes it so moist.
Over thirty minutes: Slowly pour a little bit of the lemonade mixture all over the cake in the pan every ten minutes (i.e. three times in total). This will allow the cake to absorb the lemonade mixture very slowly. You should NOT have used all of the lemonade mixture at this point.
After thirty minutes, tip the lemon cake onto a serving plate and add the remaining lemonade to the top of the cake, distributing it evenly all over the cake. NOTE: If you feel that the cake is still too dry, you may make a little more of the lemonade.
Garnish the cake with finely chopped hazelnuts and enjoy!