Line the baking tray with the graham crackers side by side.
Melt the butter and sugar over medium heat in a saucepan. Allow it to boil, then turn the heat to medium-low for 4 minutes, constantly stirring. If you stop stirring, the butter and sugar will separate and mess up the recipe. Pour this evenly over top of the graham crackers.
Bake this at 350F for 8 minutes. Once done, remove from oven.
Add the chocolate chips to a heatproof bowl and place over a saucepan filled with water over low-medium heat on the stovetop, constantly stirring (this is a double boiler method, so the chocolate is not in direct contact with the heat).
Once the chocolate is fully melted, pour over top of the graham cracker toffee in the baking dish. Immediately sprinkle with chopped pecans.
Place in the fridge or freezer for 2 hours to harden. Once hardened, cut into pieces and serve! See storage notes below.