Lemon Squares

When I saw Lavanya's Lemon Squares two weeks ago, I knew then I was going to love those and would bake them myself. Besides Lavanya, another recipe created by Carole Clements (cook's companion) has inspired me to adjust the recipe.
The balance of sweet and sour makes "Lemon Squares" a favourite tea treat for all. To ensure the crust crumble, it is important to have it pre-baked before adding the lemon filling.

Hazelnut Crust	Lemon Layer
80 g German #405 flour 20 g Icing sugar 60 g Hazelnut, ground Pinch of salt 100 g Unsalted cold butter, diced	2 Eggs 100 g Sugar 60 ml Freshly squeezed lemon juice 1 tsp Lemon rind, finely grated 2 tbsp German #405 flour 1/2 tsp Baking powder

1. Preheat the oven to 180C/350F. Lightly grease a 20x25 cm baking dish. Sift the flour, icing sugar, ground hazelnut and salt into a mixing bowl. Using your fingers or a pastry blender, rub in the butter until the mixture resembles coarse breadcrumbs.
   
2. Mix with a fork until the mixture forms a ball. Press the mixture evenly into the baking dish and bake until light golden brown, about 15 minutes. Remove and let cool slightly. Beat the eggs and sugar until smooth. Add the lemon juice and zest and stir to combine. Mix together the flour and baking powder and add into the lemon mixture. Fold to combine.
3. Pour the filling over the shortbread crust and bake for about 20-25 minutes until the filling is set. Remove from oven and place on a wire rack to cool. Cut into 5x5 cm squares and dust with icing sugar.