1. Heat oven to 350F. Beat brownie mix, melted butter, cream cheese and egg in medium bowl 50 strokes with spoon until well-blended (dough will be sticky)
2. Drop dough by rounded tablespoonsful 2 in. apart onto ungreased cookie sheets to make 24 cookies, smooth edges to form round cookies.
3. Mix powdered sugar and peanut butter in sm. bowl with spoon until mixture forms a ball. With hands, roll rounded spoonfulls of peanut butter mixture into 24 balls. Lightly press 1 ball of peanut mixture into center of each ball of brownie dough.
4. Bake 10 to 14 min. or until edges are set. Cool on cookie sheets at least 30 min.
5. Spread thin layer of frosting over peanut butter portion of each cooled cookie.
High altitude (above 3500 ft): Flatten cookies slightly before baking at 350F for 11-15 min.