1cupsifted powdered sugar, you can use as little as ⅔(100 grams)
Instructions
Preheat oven to 325 degrees F. Line an 8 ½ by 4 ½ inch loaf pan with a double layer of foil and grease the bottom only.
In a 1 ½ to 2 quart saucepan set over medium low heat, melt the butter, then add the cocoa powder. Stir until smooth. Add the sugar and stir just until it begins to shine. Remove from heat. Let cool slightly and beat in a cold egg. When egg is fully blended, stir in salt and flour. Let cool for about 10 minutes.
Make sure mixture is not so warm it will melt the chips, then stir in the chocolate chips.
Scrape the batter into the prepared pan and spread evenly.
Bake the brownie at 325 degrees F for 18 to 20 minutes or until the brownies' internal temperature tops out at 200 degrees F. For these, it's probably best to underbake than overbake, so be careful not to over-bake.
Remove warm brownies from the oven. Microwave peanut butter for about 30 seconds and spread over the top of the brownies. Let cool for a few minutes at room temperature, then transfer to the refrigerator and chill for another 20 minutes or until peanut butter is somewhat firm.
Prepare topping. Make sure you've already sifted and weighed your powdered sugar because it needs to be ready to go.
Clean out the saucepan you used for the brownie batter. Melt the butter and marshmallows together. When the marshmallows are very soft and almost fully melted, add cocoa powder and milk, Stir until smooth. Gradually add half the powdered sugar and begin stirring. remove from heat and stir until smooth, adding remaining powdered sugar gradually.
Stir until smooth and shiny, then pour mixture over the set peanut butter brownies. Put in the freezer for about 20 to 30 minutes (or you can just let sit at room temperature for a while), then lift from loaf pan. Trim edges and keep them for yourself, then cut the rest into 8 neat squares.
Notes
The version of this recipe in the 1992 Southern Living Annual calls for butter or margarine. Whenever I see something that says "or margarine" that's a clue that it was developed with salted butter, so if you want to try using salted butter along with the ⅛ teaspoon of salt, it should be fine.