Boil butter and sugar until it reaches 298 degrees on a candy thermometer.
Pour toffee over pretzels and spread smooth with an offset spatula.
Melt chocolate in a double boiler.
Then pour chocolate over the toffee and smooth out with an offset spatula.
shake sprinkles on top of the chocolate.
Let the chocolate and toffee cool completely before cutting. You can put the tray in the fridge to set it up faster if you are in a hurry.
Cut or break apart toffee and get everyone addicted to this, it will only take one piece I'm sure!
Notes
I used a block of chocolate that is for candy making, I find it doesn't have a waxy coating like chocolate chips and tempers easily, so when the toffee is set up, the chocolate will no be soft at room temperature.