Preheat oven to 350 degrees. Spray a 13” x 9” baking dish with non-stick cooking spray and then line with parchment paper so that the edges of the paper overhang the dish (to easily remove the bars).
Make the shortbread crust first. In a medium bowl, combine all of the crust ingredients. Mix with a rubber spatula until it forms a dough.
Evenly press the shortbread dough into the prepared baking dish. Bake the crust for 20-25 minutes until it is lightly golden around the edges (it may still look pale in the middle).
While the crust is baking, prepare the lemon filling. In a large bowl, combine the flour, sugar, and lemon zest and stir until combined. Then add the whisked eggs, lemon juice, and heavy cream. Whisk very well until thoroughly combined.
When the crust is done baking, gently poke the top with a fork in a few spots, being sure to NOT pierce all of the way through. Give the lemon filling a whisk for another few seconds and then pour it over the crust.
Bake the bars in the oven for 20-25 minutes until the lemon filling is completely set in the middle (and doesn’t wobble). Let the bars cool at room temperature for 1-2 hours. Once cooled, place the bars into the refrigerator until chilled (at least another 1-2 hours).
When the lemon bars have chilled, gently pull up on the overhanging parchment paper until the bars are released from the baking dish. Cut the lemon bars into 24 squares and then dust the top with sifted confectioner’s sugar.
Refrigerate leftovers in an air-tight container for up to one week. The bars are best when eaten in the first few days. Enjoy!