1. Preheat oven to 350°. Line bottom and sides of an 8-inch square pan with aluminum foil, allowing 2 to 3 inches to extend over sides; lightly grease foil.
2. Prepare brownie batter according to package directions for fudgy brownies, stirring vanilla into batter. Pour batter into prepared pan.
3. Place cream cheese in a microwave-safe bowl. Microwave at HIGH 15 seconds. Add peanut butter, and stir until smooth and blended. Drop peanut butter mixture by 16 rounded teaspoonfuls onto batter. Sprinkle candies over batter.
4. Bake at 350° for 50 to 53 minutes or until a wooden pick inserted in center comes out with a few moist crumbs. Cool completely on a wire rack (about 1 hour). Lift brownies from pan, using foil sides as handles. Place on a cutting board, and cut into 16 squares.