Cake Mix Cream Cheese Cookies

1/4 cup butter or margarine, softened
1 pkg. (8 oz. ) cream cheese, softened
1 egg yolk
1/4 tsp. vanilla
1 pkg. yellow cake mix

Cream butter and cream cheese. Blend in egg yolk and vanilla. Add dry cake mix 1/3 at a time, mixing well after each addition. If mixer is used, add last third of cake mix by hand. Cover and chill for 1 hour,
Preheat oven to 375*. Drop by rounded teaspoonfuls onto ungreased baking sheet. Bake for 8-12 minutes, or until light golden brown.