Preheat oven to 350°F Grease a 17x11 baking sheet and line with parchment paper overlapping the two ends for easy removal.
COOKIE: Beat butter, sugars, vanilla and water until smooth. Add remainin 3 ingredients and beat until mixture is combined.
Spread dough to cover prepared baking sheet.
Bake in preheated oven for 15 minutes.
TOPPING: Meanwhile, over medium heat bring butter and brown sugar to a boil. Stir to combine. Spread mixture over partially baked cookie dough. Return to oven and bake an additional 8 minutes until caramel is bubbling.
Remove from oven. Immediately sprinkle chocolate chips over hot caramel. Wait 5 minutes and spread melted chocolate over cookie, if using nuts, sprinkle over chocolate.
Cool in refrigerator until chocolate is set. Once at room temperature, break or cut slab into irregular pieces or into your favorite cookie cutter shapes.