Lemon Sandwich Cookies — Three Many Cooks

Ingredients

• 1 whole egg, plus 1 yolk
• 1 teaspoon vanilla extract
• ½ teaspoon salt
• 2 sticks (16 tablespoons) unsalted butter, at cool room temperature
• 1 cup granulated sugar
• 1 tablespoon finely grated lemon zest
• 2½ cups all-purpose flour
• 1 package (8 ounces) cream cheese, softened
• 4 tablespoons unsalted butter, softened
• ½ teaspoon vanilla extract
• ¾ cup confectioner’s sugar