1. Preheat oven to 350 degrees. Prepare a 9 by 9 inch baking pan by spraying it with nonstick spray and lining it with parchment paper, leaving excess paper hanging over the sides for easy removal after baking.
2. In the bowl of an electric mixer, cream together butter and sugar on medium low speed. Add flour and mix until a dough is formed. Press the dough into the bottom of the 9 by 9 inch baking pan. I use a small piece of parchment paper to press the dough so that it won’t stick to my fingers.
3. Bake for 15 minutes at 350 degrees.
4. In the meantime, make the filling.

For the Filling

1. In the bowl of an electric mixer, whisk eggs and sugar until smooth. Add flour and mix, then add lemon juice and raspberries. Make sure the raspberries are a little bit crushed up by the whisk so that they can be evenly distributed through the filling. When the crust comes out of the oven, pour the filling over the crust. Return to the oven, and bake for another 20 minutes.
2. Cool completely and then dust with powdered sugar. Use the parchment paper handles to lift the bars out of the pan to make cutting easier.
3. If garnishing with lemon slices, whole raspberries, and mint leaves, do this just before serving.