Line an 8x8 pan with foil and spray with cooking spray. Set aside. Melt the butter in a medium saucepan over medium heat. Add the marshmallows.

Stir until melted. It takes about 3 minutes.

Take the pan off of the heat and add both chips.

And pretzel pieces.

Line an 8x8 pan with foil and spray with cooking spray. Press the mixture into the pan.

Sprinkle with sea salt.

Allow to cool before cutting. Lift the bars out of the pan and cut into squares.

I dipped mine in chocolate and sprinkled it with extra salt.