In 2-cup measure, microwave chocolate with butter at Medium for 3 to 4 minutes or until melted, stirring once. Let cool slightly.

In bowl, beat sugar with eggs; blend in chocolate mixture and vanilla. Combine flour, baking powder and salt; blend into chocolate mixture. Stir in peanut butter chips. Spread in ungreased 8-inch square baking dish. Microwave at High for 4 1/2 to 5 minutes or until top is no longer sticky, rotating dish once. Let stand on countertop for 10 minutes. Set on rack and let cool completely.

Topping: Meanwhile, in small bowl, combine chocolate and 1 tablespoon of the oil; microwave at Medium for 2 to 2 1/2 minutes or until melted, stirring twice. In separate bowl, mix peanut butter chips with remaining oil; microwave at Medium for 1 to 2 minutes or until melted, stirring once.

Spread chocolate mixture over brownies. At 1-inch intervals, drizzle with bands of peanut butter mixture. Pull tip of knife at right angles through bands. Pull knife through bands in opposite direction. Refrigerate for 1 hour or until topping is set. Cut into squares.

Per serving: 298 Calories; 18g Fat (51% calories from fat); 4g Protein; 34g Carbohydrate; 39mg Cholesterol; 132mg Sodium

chips in both the base and topping.