Makes 190 to 200 cookies.
"My husband, being the chocolate lover that he is, absolutely loves these cookies. They are prepared with cocoa powder and lots of top-quality semisweet chocolate chips. The dark brown sugar complements all the chocolate, and the end result is a decadently rich cookie."
Preheat the oven to 350 F. Lightly grease 3 cookie sheets or line with parchment paper.
In a large mixing bowl, cream the butter until smooth. Add the brown sugar and cream well. Add the egg and vanilla and mix until fully incorporated.
Sift together the cocoa, flour, baking soda, and salt into another bowl. Add to the butter mixture and mix until it begins to come together. Add the chocolate chips and mix until a dough forms.
Roll the dough into 3/4-inch-thick logs. (The length doesn't matter.) Slice into 1/2-inch lengths. Place the cookies, cut side down, 1 inch apart on the prepared cookie sheets.
Bake one pan at a time on the middle rack of the oven for 6 to 8 minutes for fudgy cookies or about 10 minutes for crisper cookies. (While one pan is baking, prepare the next cookie sheet.) Place cookie sheet on a rack to cool.