Heat oven to 350°F. In large bowl, beat butter and brown sugar with electric mixer on medium speed until light and fluffy. Beat in vanilla and egg. Add Bisquick mix; beat on low speed until combined. Stir in chocolate chips.
Onto ungreased cookie sheets, drop dough by tablespoonfuls about 2 inches apart.
Bake 8 to 10 minutes or until set on edges and golden brown. Cool on cookie sheets 2 minutes. Remove from cookie sheets to cooling racks.
