1. Cream butter; gradually add sugar, beating until light and fluffy.
2. Add half-and-half and vanilla.
3. Combine flour, cocoa, and soda; add to creamed mixture, beating just until blended.
4. Stir in chopped pecans and chocolate chips.
5. Drop dough by heaping teaspoonfuls 1 1/2 inches apart on ungreased cookie sheets.
6. Bake at 350 degrees for 10 to 12 minutes (do not overbake).
7. Cool slightly on cookie sheet before moving to a rack.