# What you'll need:
→ Shortbread Crust
01 - 1 cup unsalted butter, softened
02 - 1/2 cup granulated sugar
03 - 2 cups all-purpose flour
04 - 1/2 tsp salt
→ Blackberry Swirl
05 - 1 cup fresh or frozen blackberries
06 - 2 tbsp granulated sugar
07 - 1 tsp lemon juice
→ Lemon Filling
08 - 1 1/2 cups granulated sugar
09 - 1/4 cup all-purpose flour
10 - 4 large eggs
11 - 2/3 cup freshly squeezed lemon juice
12 - Zest of 2 lemons
# How-To Steps:
01 - Preheat oven to 350°F. Line a 9x9-inch baking pan with parchment paper, leaving some overhang for easy removal.
02 - In a medium bowl, cream together butter and sugar until light and fluffy. Add flour and salt, mixing until the dough comes together. Press the dough evenly into the prepared pan. Bake for 18–20 minutes, or until lightly golden.
03 - In a small saucepan, combine blackberries, sugar, and lemon juice. Cook over medium heat, mashing the berries and stirring, until thickened (about 5 minutes). Strain through a sieve to remove seeds and set aside.
04 - In a large bowl, whisk together sugar and flour. Add eggs, lemon juice, and zest, whisking until thoroughly combined.
05 - Pour the lemon filling over the pre-baked crust. Dot spoonfuls of the blackberry puree over the filling, then use a toothpick or knife to swirl gently.
06 - Bake for 20–22 minutes more, until the center is just set and the top looks slightly matte.
07 - Cool completely in the pan, then refrigerate for at least 2 hours before lifting out and slicing into bars. Dust with powdered sugar if desired.
