# What You Need:
→ For the Shortbread Crust
01 - 1 cup (225 g) unsalted butter, softened
02 - 1/2 cup (100 g) granulated sugar
03 - 2 cups (250 g) all-purpose flour
04 - 1/2 tsp salt
→ For the Blackberry Swirl
05 - 1 cup (150 g) fresh or frozen blackberries
06 - 2 tbsp (25 g) granulated sugar
07 - 1 tsp lemon juice
→ For the Lemon Filling
08 - 1 1/2 cups (300 g) granulated sugar
09 - 1/4 cup (30 g) all-purpose flour
10 - 4 large eggs
11 - 2/3 cup (160 ml) freshly squeezed lemon juice (about 3–4 lemons)
12 - Zest of 2 lemons
# Step-by-step guide:
01 - Preheat oven to 350°F (175°C). Line a 9x9-inch (23x23 cm) baking pan with parchment paper, leaving some overhang for easy removal.
02 - In a medium bowl, cream together butter and sugar for the crust until light and fluffy. Add flour and salt, mixing until the dough comes together.
03 - Press the dough evenly into the prepared pan. Bake for 18–20 minutes, or until lightly golden.
04 - While the crust is baking, make the blackberry swirl: 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. Set aside.
05 - For the lemon filling, whisk together sugar and flour in a large bowl. Add eggs, lemon juice, and zest, whisking until thoroughly combined.
06 - 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.
07 - Bake for 20–22 minutes more, until the center is just set and the top looks slightly matte.
08 - 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.
