1-First Steps: Getting Started Preheat your oven to 350°F (175°C) and grease a 9×13-inch baking pan to prevent sticking. In a medium bowl, mix the softened butter and ½ cup sugar until fluffy; add the lemon zest for that fresh kick. For vegan or low-calorie alternatives, use plant-based butter and sweeteners respectively to keep it simple.

2-Mixing and Baking the Crust: Combine 2 cups all-purpose flour and ¼ teaspoon kosher salt in another bowl, then mix into the butter mixture until just combined. Press the dough evenly into the prepared pan and chill for 15 minutes. Bake the crust for 15-20 minutes until lightly browned, then let it cool for 30 minutes while the oven stays at 350°F. This step ensures a sturdy base, which is key for the best texture. During this time, you can prepare the raspberry puree by whisking 2 tablespoons granulated sugar, 2 teaspoons cornstarch, and ¼ cup lemon juice in a saucepan.

3-Adding the Puree and Filling: Add 1 cup raspberries to the saucepan and cook over medium heat, whisking constantly until thickened and bubbly, about 6 minutes, then strain to remove seeds and set aside. For the lemon filling, whisk 7 large eggs, 3 cups granulated sugar, 2 tablespoons grated lemon zest, and 1 cup all-purpose flour together in a bowl. Gradually add 1 cup freshly squeezed lemon juice and whisk well until smooth. Pour this filling over the cooled crust, then drop spoonfuls of the raspberry puree across the top and swirl with a toothpick for that pretty marbled look.

4-Final Baking and Cooling: Bake for 30-35 minutes until the filling is set, then cool completely to room temperature. Once cooled, refrigerate the bars ideally for 1 day to let the layers settle before cutting into squares or triangles. Dust with confectioners’ sugar just before serving to add a sweet finish.