Preheat oven to 375 degrees. Line a 15x10 baking pan with foil leaving a 2 inch overhang at each end.
Line bottom of pan with graham crackers. Will be a very tight fit.
Melt butter in a small saucepan over low heat, add brown sugar and salt. Cook, whisking entire time, until mixture is smooth and combined well. About 1 minute. DO NOT LET THIS MIXTURE BURN.
Pour over crackers, spreading evenly and bake in the middle rack until golden brown and bubbly. About 10 minutes.
Remove from oven and gently scatter chocolate chips evenly over crackers and place back in over for another minute until chocolate is soft.
Remove pan from oven and gently spread chocolate evenly over crackers with offset spatula.
Sprinkle nuts evenly over chocolate and cool crackers on a rack for 30 minutes. Or if you prefer, you can freeze 10-15 minutes. If you choose to freeze this make sure you press the nuts into the chocolate so they stick.
Carefully lift crackers from pan by grasping both ends of the foil, then peel foil from crackers. Break crackers into serving pieces and enjoy!