• 1 cup (2 sticks) unsalted butter, at room temperature
• 1 cup confectioners’ sugar
• 1 large egg
• 2½ tsp. vanilla extract
• 1 vanilla bean slit lengthwise optional
• Zest of half a lemon up to a whole lemon for a strong flavor
• 2½ cups all-purpose flour
• 1 tsp. salt

Alternative flavor: Reduce vanilla extract to 1 tsp and skip the vanilla bean and lemon zest. Add

• 1 1/2 tsp almond extract