In a medium bowl, cream together the butter, white sugar, egg yolk and vanilla until smooth. Stir in the flour until well blended, then mix in coconut raisins and pecans (if desired). Chill for at least 4 hours or overnight.
Preheat the oven to 325 degrees F (165 degrees C). Grease cookie sheets. Roll tablespoonfuls of dough into balls or logs and place them 2 inches apart onto the prepared cookie sheets.
Bake for 25 to 30 minutes in the preheated oven, or until lightly browned. Remove from cookie sheets to cool on wire racks.
