Pre-heat oven to 350 degrees F. Line a 9 x 9-inch square baking pan with parchment paper and set aside.
In a large bowl with a hand or stand mixer, beat together the softened butter and sugar until fluffy.
Add vanilla extract and mix until combined. Be sure to scrape down the sides of the bowl.
Slowly add in the flour, mixing until shortbread dough has formed. Be sure not to over-mix.
Spread shortbread dough into the prepared baking pan and evenly spread with a rubber spatula or your hands. Bake the crust for 20-25 minutes until the top is lightly browned.
In the meantime in a medium or large mixing bowl, whisk together the eggs, sugar, lemon zest and juice. Sift flour and add to the mixture. Mix until the lemon mixture is smooth.
When the crust is done baking, let cool for a few minutes then add cranberry sauce (the crust should still be warm, this will help the layers stick).
Add the lemon layer on top and bake for another 30-35 minutes. Let the bars cool completely and then place in the refrigerator to set and get cold for a few hours to overnight. Dust the tops with powdered sugar and cut into 16 bars and enjoy!