Tangy Lemon Squares

– A buttery shortbread base topped with an extra tangy layer of golden lemon goodness.


For the base:

  • 1 cup all-purpose unbleached flour
  • ¼ cup granulated sugar
  • ½ teaspoon kosher salt
  • 8 tablespoons butter, melted


For the filling:

  • 1 cup granulated sugar
  • 2 tablespoons all-purpose unbleached flour
  • 2 teaspoons cream of tartar
  • ½ teaspoon kosher salt
  • 3 eggs, room temperature
  • 3 yolks, room temperature
  • 2 teaspoons lemon zest
  • 2/3 cup freshly squeezed lemon juice
  • 4 tablespoons butter
  • icing sugar for dusting



1. Preheat oven to 350°F, rack in the middle position. 

Line an 8 x 8-inch square baking pan with two sheets of foil laid criss cross in the centre with an inch of foil overhanging each side.

2. Make the base: Stir flour, sugar and salt together in a medium-sized bowl. Add melted butter and stir to combine. Transfer into baking pan, pressing the mixture down into an even layer. Bake for 20 minutes or  until surface is lightly golden.

3. Make the filling: While the base is baking, place sugar, flour, cream of tartar and salt and stir. Add eggs  and egg yolks and whisk. Transfer to a medium-sized saucepan on a low-moderate heat. Heat slowly,  stirring continuously until mixture thickens, 6 to 8 minutes. Remove from heat, add butter and stir until butter. Pass mixture through a fine sieve to remove lumps.

4. Assemble squares: Remove base from oven. Pour warm filling on top, tilting the pan gently to get an even  layer of filling across the surface. Return to oven and bake for an additional 10 minutes or until the filling sets.

5. Remove from oven and cool for at least 1½ hours, preferably cooling completely.