Spray a 13x9-inch baking dish with nonstick spray; set aside. Melt 1 cup butter in a medium saucepan over medium-high heat. Reduce heat to low; add milk chocolate chips, semisweet chocolate chips, and butterscotch chips. Cook until melted, stirring frequently. Stir in peanut butter until well combined.

Spread half of chocolate-peanut butter mixture in prepared baking dish. Refrigerate for 10 to 15 minutes or until mixture is completely set. Transfer remaining chocolate-peanut butter mixture to a medium microwave-safe bowl; stir in 2 cups peanuts and set aside.

Melt remaining 1 cup butter in another medium saucepan over low heat. Stir in pudding mix, powdered sugar, marshmallows, and maple extract. Cook and stir just until marshmallows are melted. Spread on top of chocolate-peanut butter layer in baking dish; freeze for 15 to 30 minutes.

Microwave chocolate-peanut butter in bowl on high for 20 to 30 seconds or until melted. Drop spoonfuls of mixture on top of pudding layer; spread to cover. Chop remaining ½ cup peanuts and sprinkle on top. Cover and refrigerate for 2½ to 3 hours or until firm.

To serve, let stand at room temperature for 10 minutes. Cup into 24 bars. Store covered in refrigerator up to 5 days.