In a large mixing bowl, cream butter and sugar; add eggs, milk, and vanilla, blending well.
In another bowl, combine the flour with baking powder, baking soda, and salt. Add flour mixture to the creamed mixture, blending well. Stir in chocolate chips. Refrigerate dough for at least 4 hours. Drop dough by teaspoonfuls onto lightly greased cookie sheets about 1 inch apart.
Bake chocolate chip cookies at 350° for about 8 to 10 minutes, or until lightly browned. Cool for a few minutes then remove to rack to cool completely.
Makes 5 to 6 dozen cookies.