Lemon Drops

ingredients
1/2  cup                  (1 stick) unsalted butter, softened
1/2  cup                   confectioners' sugar
3   tablespoons         fresh lemon juice
1   teaspoon             vanilla
1 3/4  cups                all-purpose flour
1/2  cup                    finely ground macadamia nuts
2   teaspoons             fresh lemon zest
1/3  cup                     confectioners' sugar (for coating)