1Heat oven to 350°F. Line 2 cookie sheets with silicone baking mats or cooking parchment paper.
2In large bowl, beat butter and brown sugar with electric mixer on medium speed until light and fluffy. Beat in vanilla, egg and food color. Add Bisquick mix and baking cocoa; beat on low speed until combined. Stir in chips.
3Drop dough by rounded tablespoonfuls about 2 inches apart on cookie sheets.
4Bake 8 to 10 minutes, but no longer than 10 minutes (mine were perfect at 8 minutes). The cookies will look underdone, but this is what you want. Cool on cookie sheets 5 minutes. Remove from cookie sheets to cooling racks.