Preheat your oven to 350°F (175°C). Grease and line an 8x8-inch baking pan with parchment paper, allowing some overhang for easy removal.
In a medium bowl, combine the flour, powdered sugar, and salt.
Add the cubed cold butter to the flour mixture and mix using a pastry cutter or your fingers until crumbly, resembling coarse sand.
Press this mixture firmly into the bottom of the prepared baking pan to form an even crust. Bake for 15-18 minutes or until lightly golden.
While the crust is baking, whisk together the eggs, granulated sugar, lemon juice, lemon zest, baking powder, and baking soda in a separate bowl until well combined.
Gently fold in the fresh raspberries into the lemon mixture. Be careful not to smash them completely; you want some whole berries for texture.
Once the crust is done, remove it from the oven and pour the raspberry-lemon mixture over the hot crust.
Return the pan to the oven and bake for an additional 20-25 minutes or until the filling is set and slightly firm to the touch.
Remove from the oven and allow to cool completely in the pan on a wire rack. Once cool, lift the bars out using the parchment overhang.
Dust the top generously with powdered sugar before slicing into squares.
Notes
Serve on a platter with a few fresh raspberries and lemon slices for a pop of color. Add sprigs of mint for an extra touch!