Ingredients:

  • 1/2 cup (113g) unsalted butter, melted and slightly cooled
  • 1/4 cup (50g) granulated sugar
  • 1 tsp vanilla extract
  • 1 cup (125g) all-purpose flour
  • 1 tbsp (8g) cornstarch
  • 1/4 tsp salt
  • 1 cup (200g) granulated sugar
  • 3 tbsp (25g) all-purpose flour
  • 3 large eggs, room temperature
  • 1/2 cup (120ml) fresh lemon juice
  • 1 tbsp finely grated lemon zest
  • 1 tbsp powdered sugar

Instructions:

  1. Preheat your oven to 350°F (175°C) and line an 8x8 inch pan with parchment paper, ensuring there is some overhang for easy removal.
  2. In a medium bowl, stir together the melted butter, 1/4 cup sugar, vanilla, 1 cup flour, cornstarch, and salt until a soft dough forms.
  3. Press the dough firmly into the bottom of the prepared pan and bake for 20 minutes until the edges are a light mahogany color and the center is set.
  4. While the crust bakes, whisk the 1 cup sugar and 3 tablespoons flour for the filling in a large bowl to remove lumps.
  5. Gently whisk in the eggs one at a time, followed by the fresh lemon juice and zest. Whisk slowly to avoid creating air bubbles.
  6. Pour the lemon filling onto the shortbread crust while it is still warm from the oven to ensure they bond and prevent a soggy crust.
  7. Return the pan to the oven and bake for an additional 25 minutes, or until the filling is set and no longer jiggles in the center.
  8. Allow the bars to cool completely at room temperature, then dust with powdered sugar before slicing into 16 squares.