Preheat oven to 350°F. Line a 15×10 inch jelly roll pan with aluminum foil, sprayed lightly with cooking spray. Place graham cracker sheets in a single layer on prepared baking sheet.
In a saucepan, bring brown sugar, butter and heavy whipping cream to a boil, over medium heat, stirring often. Once melted and smooth, add vanilla.
Pour caramel sauce over the graham cracker sheets and spread into an even layer. Sprinkle with chopped pecans.
Bake for 10 minutes, until lightly golden brown and bubbly.
Remove from oven and sprinkle with salt. Carefully lift out the bars (using the aluminum foil) and cool on wire racks about 30 minutes, or until completely cooled.