Cream butter, confectioner's sugar and vanilla. Blend in flour with beater or spoon; chill.
Using 2 teaspoons of the dough for each cookie, make into small balls (approximately 1-inch). Place on ungreased cookie sheet and make an indentation in the center of each with a finger. Indentation will widen during baking.
Bake in moderate oven (350 degrees) until straw colored around the edges, about 10 to 15 minutes.
Remove from oven, working quickly while cookies are still very hot and on pan, place semi-sweet chocolate chips and filberts in the indentations. Remove to racks to cool. Chocolate chips will melt from heat of cookies and keep filberts in place. Makes 24 cookies.