1/2 cup and 2 tablespoons butter, softened
1 cup sugar
1 teaspoon vanilla extract
1 cup flour
1/4 cup and 2 tablespoons unsweetened cocoa powder
1/2 teaspoon baking soda
1/4 teaspoon salt
1 cup semisweet chocolate chips
Preheat oven to 350 degrees F (175 C)
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the egg, then stir in the vanilla. Sift together the flour, cocoa, baking soda, and salt. Stir into the creamed mixture until blended. Stir in the chocolate chips. Drop dough by teaspoonsful onto ungreased cookie sheets.
Bake 8 to 9 minutes. Cookies will be soft: cool slightly on cookie sheet. Remove to wire rack to cool completely.