• Preheat the oven to 350 degrees F.

For the Shortbread Crust:

• Line a 6 x 6 inch cake pan with a piece of parchment paper, with some paper sticking out on two sides for easy removal.
• Spray the pan and parchment with non-stick spray.
• Cream the butter and sugar in a stand mixer with the paddle attachment.
• Add the flour and mix until small crumbles form.
• Dump the crust crumbles into the prepared pan and press the crust flat into the pan with your fingers.
• Bake for 20 minutes until the crust is just barely browned on top.
• While the crust is baking, mix the filling.

For the Lemon Filling:

• Beat together the eggs, sugar, lemon juice, and flour.
• When the crust is done, pour the filling on top of the crust and place back into the oven for 40 minutes or until the filling no longer jiggles when tapped and is set. It should be lightly browned on top as well.
• Cool to room temperature or chill in the refrigerator, about 1 hour. Cut into 4 bars and dust powdered sugar over the top.