Preheat your oven to 350 degrees. Line a baking sheet with nonstick parchment lined foil or aluminum foil sprayed with nonstick spray. Place all of the crackers in a single layer on the baking sheet.
In a medium saucepan over medium-high heat stir the butter and sugar until it comes to a boil.Once it has come to a boil reduce the heat to medium and let it simmer for 5 minutes.
Once the chocolate starts to melt use a non stick spatula spread it across the whole top of the toffee. Sprinkle the coarse salt on top of the chocolate.