Line 9x9 inch baking pan with parchment paper.
In a large pot, over medium-high heat, melt butter. Then add brown sugar and stir until dissolved. Stir in heavy cream and whisk continually until it starts to boil.
Once everything is combined and boiling, turn heat down to medium-low, add the peanut butter and marshmallows. Stir constantly with a wooden spoon until melted. Remove from the heat and add rice krispie cereal and salt until well coated.
Transfer the cereal to the prepared pan and press down evenly.
Over a double boiler, melt the chocolate chips and peanut butter together until smooth.
Spread the chocolate mixture over the rice krispie layer. Chill in the fridge for at least 30 minutes before cutting.
