For bars: Coat 13x9" pan with cooking spray. Melt butter in a large saucepan over low heat. Add marshmallows, salt and vanilla and continue to cook, stirring constantly, until completely melted.

Remove marshmallow mixture from heat and add stir in cereal until well coated. Press mixture evenly into prepared pan. (Use a silicone spatula or wax paper to prevent the marshmallow from sticking to your hands)

For topping: Pour white chocolate chips into a microwave safe bowl. Microwave until fully melted and smooth, stirring after every 30 seconds. Drizzle melted chocolate over bars (I used a fork, drizzling the chocolate from a few inches above the bars for a more even coating).

In another bowl, mix together the butter and peanut butter. Add powdered sugar, 1 tablespoon at a time, mixing after each addition. Once well mixed, add milk, 1 tablespoon at a time, until the mixture is smooth enough to drizzle. Drizzle over bars.

Cover pan and refrigerate until firm. Cut into squares to serve. Enjoy!