1 stick of unsalted butter, softened
1/3 cup granulated sugar
1/4 tsp vanilla extract
1 cup flour
1/8 tsp salt
For the Lemon filling:
3 eggs
1 1/3 cup sugar
The zest of 1 1/2 lemons
6 tbs lemon juice (about 2 lemons)
3/8 cup (6 tbs) flour
Confectioners' sugar