Instructions:

1. Preheat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper, leaving a bit of overhang on the sides for easy removal.

2. In a mixing bowl, whisk together flour, sugar, and salt. Cut in the cold butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs. Stir in the vanilla.

3. Press two-thirds of the mixture firmly into the bottom of the prepared pan to form the crust. Reserve the remaining third for the crumble topping.

4. Bake the crust for 15 minutes, or until lightly golden. Remove from oven and set aside.

5. In a medium bowl, whisk together the eggs and sugar until smooth. Add the flour, lemon zest, lemon juice, and a pinch of salt. Whisk until fully combined and slightly thickened.

6. Pour the lemon filling over the warm crust.

7. Sprinkle the reserved crumble mixture evenly over the top of the lemon filling.

8. Bake for 20–23 minutes, or until the filling is set and the topping is golden brown.

9. Let the bars cool in the pan for about 30 minutes, then transfer to the fridge to chill for at least 1 hour before slicing.

10. Once fully set, use the parchment overhang to lift out and cut into squares.