Preheat oven to 375 degrees. Cream the butter, confectioners sugar, and vanilla in a bowl with an electric mixer until light and fluffy. Add flour and walnuts. Beat low speed until combined. Shape a small amount of the dough around each chocolate kiss, forming a sphere. Place on an ungreased cookie sheet. Bake for 12 mins, or until the cookies are set but not brown. Roll the warm cookies in additional confectioners sugar. Cool on a wire rack. These are so good and go very quickly. Makes 36 kisses.