3/4 cup butter or margarine, softened 3/4 cup sugar 1 egg yolk 1 teaspoon vanilla extract 1 1/4 cup all-purpose flour 3/4 cup crushed potato chips 3/4 cup finely chopped walnuts or pecans 3 tablespoons sugar (for dipping)
Preheat oven to 375 degrees F.
In large mixing bowl, cream butter or margarine, sugar, egg yolk and vanilla until light and fluffy. Add flour, potato chips and chopped walnuts; mix well. Form into 1 1/2-inch balls and place 3 inches apart on ungreased cookie sheet. Grease the bottom of a glass that is about 3-inches in diameter.
Dip greased glass into sugar and use to flatten each ball. Place nut half into center of each cookie. Bake for 8 to 10 minutes. Cool slightly before removing from cookie sheet. Cool on wire racks.