Credit: Annie Eats Yield: depends on size of sugar cookie INGREDIENTS 1 cup (8 oz.) unsalted butter, at room temperature 1 cup confectioners’ sugar 1 large egg 2½ tsp. vanilla extract 1 vanilla bean, split lengthwise Zest of half a lemon (or the zest of a whole lemon, if you love lemon) 2½ cups all-purpose flour 1 tsp. salt DIRECTIONS In…