Ingredients:

  • 2 cups (250 g) All-purpose flour (for crust)
  • 1/2 cup (60 g) Powdered (Icing) sugar (for crust)
  • 1 cup (225 g) Unsalted butter, very cold, cut into 1-inch cubes
  • 1/2 tsp (3 g) Fine sea salt
  • 2 cups (400 g) Granulated sugar (for filling)
  • 4 large eggs, at room temperature
  • 2/3 cup (160 ml) Freshly squeezed lemon juice
  • 2 Tbsp (15 g) Lemon zest (from 2 lemons)
  • 1/4 cup (30 g) All-purpose flour (for filling)
  • 1/2 tsp (2.5 g) Baking powder
  • 1/4 cup Powdered (Icing) sugar, or to taste (for dusting)

Instructions:

  1. Preheat the oven to 350°F (175°C). Line the 9x13 inch pan with parchment paper, leaving an overhang 'sling' for easy removal later.
  2. Whisk together the 2 cups of flour, powdered sugar, and salt in a large bowl to prepare the crust dry ingredients.
  3. Using a pastry cutter or stand mixer, cut the cold butter into the flour mixture until the mixture resembles coarse breadcrumbs or wet sand. Do not overmix.
  4. Evenly press the shortbread dough into the bottom of the prepared pan. Use the bottom of a measuring cup or glass to ensure a compact, flat base.
  5. Bake the crust for 20 minutes, or until the edges are lightly golden brown (par-baking). Remove the pan from the oven and keep the oven running.
  6. While the crust bakes, prepare the filling. In a separate bowl, whisk the 4 large eggs until frothy (about 1 minute).
  7. Whisk in the granulated sugar and lemon zest until smooth and the sugar is mostly dissolved.
  8. In a small separate bowl, whisk the remaining 1/4 cup of flour and baking powder together. Add this dry mixture to the lemon/egg mixture and whisk gently until just combined.
  9. Slowly whisk the fresh lemon juice into the filling mixture.
  10. Carefully pour the lemon filling over the hot, par-baked crust.
  11. Return the pan to the oven and bake for 25–30 minutes. The filling is done when the edges are set and a gentle shake of the pan only produces a slight jiggle in the very centre.
  12. Cooling is mandatory: Allow the bars to cool completely on a wire rack for at least 2 hours at room temperature. For the cleanest cut, chill the fully cooled bars in the refrigerator for an additional 30 minutes to 1 hour.
  13. Use the parchment paper sling to lift the entire slab of lemon bars out of the pan and place on a cutting board.
  14. Dust generously with powdered sugar just before serving. Use a large, sharp knife, wiping the blade with a warm, damp cloth between each slice, and cut into 16 squares.