Ingredients:
- 1 1/2 cups All-Purpose Flour
- 1/4 cup Granulated Sugar
- 1/4 teaspoon Fine Sea Salt (for crust)
- 1/2 cup (1 stick) Unsalted Butter, very cold, cubed (for crust)
- 1/2 cup (1 stick) Unsalted Butter, melted and slightly cooled (for filling)
- 1 cup Packed Light Brown Sugar
- 1/2 cup Light Corn Syrup or Golden Syrup
- 2 large Eggs, lightly beaten
- 1 teaspoon Vanilla Extract
- 1 teaspoon White Vinegar or Lemon Juice
- Pinch Salt (for filling)
- 1/2 cup Optional Mix-ins (Raisins or Pecans, chopped)
Instructions:
- Preheat the oven to 350°F (175°C). Line the 8x8 inch metal baking pan with parchment paper, leaving an overhang on all sides.
- Mix Dry Ingredients: In a medium bowl, whisk together the flour, sugar, and salt for the crust.
- Cut in Butter: Using a pastry blender or fingertips, cut the cold butter cubes into the flour mixture until the mixture resembles coarse crumbs.
- Press the Crust: Press the mixture firmly and evenly into the prepared pan, ensuring the corners are well-packed to form a sturdy base.
- Blind Bake: Bake the crust for 15 minutes until it is lightly set. Remove from the oven but keep the oven running.
- Melt the Butter: Melt the ½ cup of butter for the filling and allow it to cool slightly (it should not be hot).
- Whisk the Filling: In a separate bowl, whisk together the brown sugar, corn syrup (or golden syrup), and the two beaten eggs until well combined and smooth.
- Add Wet Ingredients: Whisk in the slightly cooled melted butter, vanilla extract, vinegar/lemon juice, and salt. The mixture should be thin and syrupy.
- Assemble: If using optional mix-ins (raisins, pecans), sprinkle them evenly over the pre-baked crust. Carefully and slowly pour the liquid filling over the warm crust.
- Final Bake: Return the pan to the oven. Bake for 20 to 25 minutes. The edges should be set, but the centre must still have a gentle, wet wobble ('jiggle'). Overbaking will prevent the filling from being gooey.
- Cool Completely: Remove the squares from the oven and place them on a wire rack. Cool completely at room temperature (at least 2 hours) until the filling is fully set. Do not attempt to cut while warm.
- Cut and Serve: Once fully cooled, use the parchment paper overhang to lift the slab out of the pan. Slice into 16 squares using a sharp, non-serrated knife.