Frosted Fluffernutter Bars--Here's The Skinny

If you’re feeling too skinny and have a little time on your hands--this recipe’s for you.  I am surprised at how many boxed-cake-mix cookie recipes there are out there.  And they are actually pretty good.  This is one of them.  Unfortunately, my daughter, Jamie, shared it with me.  And I made them.  More than once.  And I ate most of them.  By myself.  So, if you're feeling skinny............... (Terry)

FROSTED FLUFFERNUTTER BARS
Bars: 　
--Combine the following--1 box yellow cake mix, 1 large egg, and 1 stick of unsalted butter (oh go ahead and use 1 stick of margarine) softened. Will be thick. Press into a sprayed 9 x 13 pan. 
--Combine ½ C creamy peanut butter, ½ C marshmallow crème, and 1 can sweetened condensed milk. Pour over crust and top with a 12-ounce bag of white chocolate chips.
--Bake at 350 for 23-25 minutes. Center will seem somewhat jiggly but will set up as it cools. Cool completely and frost.

Frosting:
Mix together--1 C marshmallow crème, ½ C creamy peanut butter, ½ C softened butter (ditto), ¼ tp vanilla, and ¼ tp salt. Gradually add 1 1/3 C powdered sugar.  Frost bars.