In a large mixing bowl, cream butter and powdered sugar until light and fluffy.
Beat in lemon juice, lemon peel and vanilla.
Gradually add flour and mix well.
Shape dough into 1-inch balls.
Place on ungreased baking sheets 2 inches apart.
Coat the bottom of a flat-bottom glass with cooking spray; dip in sugar.
Flatten cookies with glass, redipping in sugar as needed.
Bake at 325° for 11 to 13 minutes until edges are lightly browned.
Remove to wire racks to cool.
Drizzle with melted vanilla chips.