Combine and beat thoroughly, all ingredients but flour, soda, and pecans.
Stir together flour and soda and add to first mixture.
Add chopped pecans.
Chill dough several hours.
Preheat oven to 350° F.
Measure out level tablespoonfuls of dough, form into balls, and place on buttered baking sheet.
Lightly press pecan half in center of each cookie.
Bake 12 minutes.
Let cookies cool a few minutes on baking sheet before removing to rack.