Step 1

Preheat oven to 350°F. Spray a 13- x 9-inch baking pan with baking spray with flour. Prepare brownie mix according to package directions in prepared pan, baking at 350°F until a wooden pick inserted in the middle comes out clean, about 25 minutes. (Baking times may vary among brownie mixes.) Cool completely, about 1 hour.

Step 2

Place peanut butter chips, sweetened condensed milk, peanut butter, vanilla, and salt in a medium microwavable bowl. Microwave on HIGH 1 minute. Stir until smooth. Spoon over cooled brownies, spreading in an even layer.

Step 3

Place chocolate chips and cream in a small microwavable bowl. Microwave on HIGH until chocolate is melted and mixture is smooth, about 2 minutes, stirring every 30 seconds. Pour over peanut butter mixture on brownies, spreading in an even layer. Refrigerate brownies until top chocolate layer is firm, about 1 hour. Sprinkle with peanuts. Slice into 32 bars.