Line a half sheet pan with a full size parchment paper so the sides of the pan are covered with paper. (This will help lift the finished product out of the pan.)
In a food processor, add the flour, salt, and powdered sugar.
Add the cubed butter and pulse on and off until incorporated. The mixture should resemble coarse sand in texture and come together when pressed.
Gently press the dough mixture out evenly onto the bottom of the sheet pan. Poke holes into the dough lightly with a fork to help prevent the pastry from bubbling. Optional: add in dried beans/ceramic baking beads to weigh down pastry.
Bake for 15-20 minutes or until just lightly brown. Do not over bake. Remove ceramic beads or beans if used.
Whisk eggs, sugar, lemon zest and lemon juice in a bowl.
In a separate bowl mix together ½ cup flour and baking powder.
Add the flour mixture into egg mixture and pour over the hot baked crust.
Bake for 25 minutes until the filling is fully set.
Let cool in pan fully before serving. Dust with powdered sugar and enjoy!