Lay Saltines, salt side down, on Parchment paper or foil sprayed with Pam. Boil butter and brown sugar until caramel color (about 2 - 3 minutes).
Pour the butter mixture over all the crackers. Bake at 375 degrees for about 5 minutes, watching carefully not to over bake.
Remove from oven and spread 8 ounces chocolates chips over all and once melted, take knife and spread over all crackers. Add chopped nuts, if desired. Place in freezer 15 - 20 minutes. Remove and break into pieces.