My suggestion is to not bother making it into any kind of bar thing. Melt the whole shebang, and throw it in a bowl. Use it as dip for apples, pretzels, whatever. It's delicious.
Peanut butter "bars"
2 cups salted peanuts
2 & 1/2 tablespoons butter
2 cups peanut butter chips
14 ounces sweetened condensed milk
2 cups miniature marshmallows
kosher salt or sea salt, optional
Instructions:
Melt butter and peanut butter chips in a large saucepan over low heat.
Stir until smooth.
Stir in condensed milk and marshmallows.
Continue stirring until smooth and well-blended.
Add in peanuts and transfer into a bowl.
Add salt if you like.
Cover and refrigerate until chilled.
