01 - Preheat the oven to 350°F. Line a 9x9-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - In a medium bowl, beat together the butter and sugar until creamy. Add flour and salt, and mix until a crumbly dough forms.
03 - Press the dough evenly into the bottom of the prepared pan. Bake for 18-20 minutes, or until the edges are lightly golden.
04 - While the crust is baking, whisk together sugar, eggs, lemon juice, and lemon zest in a large bowl until smooth. Whisk in the flour until fully combined.
05 - Gently fold in the raspberries, being careful not to crush them completely.
06 - Pour the filling over the hot crust as soon as it comes out of the oven.
07 - Return the pan to the oven and bake for 20-22 minutes, or until the center is just set and no longer jiggles.
08 - Cool completely in the pan on a wire rack. Once cool, refrigerate for at least 2 hours for easier slicing.
09 - Lift out of the pan using the parchment overhang. Dust with powdered sugar before slicing into bars. Garnish with extra raspberries if desired.