Preheat the oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, leaving an overhang for easy removal.
In a large bowl, beat together the butter and sugar until light and creamy.
Mix in the flour and salt until a soft dough forms.
Press the dough evenly into the prepared baking pan.
Bake the crust for 18 to 20 minutes, or until lightly golden around the edges.
While the crust bakes, whisk together the granulated sugar and flour.
Add the eggs, lemon juice, and lemon zest, whisking until smooth.
Scatter the raspberries evenly over the warm crust.
Pour the lemon filling over the raspberries.
Use a toothpick or knife to gently swirl a few raspberries into the filling without overmixing.
Bake for 22 to 26 minutes, or until the center is set and no longer jiggles.
Cool completely at room temperature, then refrigerate for at least 2 hours.
Lift the bars from the pan, dust generously with powdered sugar, and slice into squares.