Melt butter and brown sugar in a pot. Cook on medium heat for 7-8 minutes or until a tan-ish brown color.
Pour toffee mixture over pretzels making sure to cover all the pretzels. Bake at 350 for 10 minutes. Take out and top with 2 cups of your favorite chocolate chips (we did half and half and used 1 cup white chocolate chips and 1 cup milk chocolate chips).
Let chips melt for a few minutes and spread with spatula to cover toffee layer. Sprinkle with any desired toppings.
Let cool at room temp or by refrigerating until hardened. Break into pieces and store in air tight container in the fridge.