Add the butter, brown sugar, confectioner’s sugar, peanut butter, vanilla, and salt to the pan. Over medium low heat, cook and stir the mixture until it’s well combined.
Once your chocolate is melted, remove the pan from the fridge and pour it on the peanut butter layer. Spread it to the edges and again, a sharp tap on the counter will remove any air bubbles.
Back into the refrigerator it goes. This time you’ll want to chill it for at least an hour. Trust me, the bars will be much easier to cut into squares if they are cold.