Cinc: Chef John's Lemon Bars

Ingredients

• 1 cup all-purpose flour
• ½ cup unsalted butter at room temperature
• ¼ cup confectioners' sugar
• ¼ teaspoon vanilla extract
• ¼ teaspoon salt
• 2 large eggs
• 1 large egg yolk
• 1 cup white sugar
• 2 tablespoons all-purpose flour
• ¼ cup freshly squeezed lemon juice
• 1 tablespoon freshly grated lemon zest
• 1 teaspoon confectioners' sugar