For the Shortbread Crust

• 1 cup (2 sticks or 226g) unsalted butter
• ½ cup (108g) granulated sugar
• ½ teaspoon lemon zest (from about 1 lemon)
• 2 cups (260g) all-purpose flour
• ¼ teaspoon salt
• 1 teaspoon vanilla extract

For the Lemon Custard

• 4 large egg yolks
• ¾ cup (150g) granulated sugar
• ½ teaspoon lemon zest (from about 1 lemon)
• ¼ cup (40g) cornstarch
• ¼ teaspoon salt
• ⅔ cup (155g) fresh lemon juice (about 3-4 large lemons)
• 1 ¼ cup (300mL) heavy cream
• 1 ¼ cup (300mL) whole milk
• 2 Tablespoons (28g) unsalted butter

For the Topping

• ½ cup granulated sugar

1. Preheat oven to 350°F. Lightly grease a 9” x 9” square pan with cooking spray. Line with parchment paper to create a sling, with an overhang on all four sides.
   
   
2. Shortbread Crust: Melt the butter and allow it to cool slightly. In a large mixing bowl, combine the granulated sugar with the lemon zest and rub it between your fingers to release the oils. To the sugar mixture, add flour and salt and whisk together until well combined. Add the melted butter and vanilla. Mix until everything is combined and no pockets of flour remain.
   
   
3. Use your fingers or a small offset spatula to evenly press the shortbread dough into the bottom of the prepared pan. Bake for 16-18 minutes, or until the edges just start to turn golden brown. While the shortbread crust is baking, make the lemon custard.
   
   
4. Lemon Custard: In a medium saucepan, whisk together the egg yolks, sugar, lemon zest, cornstarch, and salt. Slowly stream in the lemon juice while whisking then stir in the heavy cream and milk. Cook over low heat and stir constantly with a heat-safe spatula until the mixture thickens and just starts to bubble, about 10-15 minutes. Remove the custard from heat and strain through a fine mesh sieve to remove the zest. Stir in the butter.
   
   
5. Pour the hot lemon custard onto the warm shortbread crust. Spread the custard out into an even layer. Return to the oven for an additional 8-10 minutes, just until the top is set and the custard starts to bubble around the edges. Allow the bars to cool to room temperature then move them to the fridge to chill for 8 hours or overnight.
   
   
6. Once the bars are chilled, remove them from the pan and slice into 16 even squares. Wipe your knife off between each cut for clean slices. Move the squares to a large empty sheet pan (no parchment paper) and freeze for about 30 minutes before torching.
   
   
7. Remove the squares from the freezer and working with 2-3 squares at a time, sprinkle an even layer of the granulated sugar over each bar. Use a kitchen torch to carmelize the sugar, holding it a few inches away and moving it in a small circular motion. Repeat with the remaining bars, torching 2-3 at a time. Cool for a few minutes to allow the sugar to harden. Serve immediately and enjoy!

‍

NOTES

• Storing: Store the bars (without the topping) in an airtight container in the fridge for up to 3 days. Sprinkle on the sugar and torch right before serving.
  
  
• Torching: Be sure to check out the blog post above for helpful tips!