1 heaping cup whole pecans, lightly chopped
Preheat oven to 350° Fahrenheit. Toast pecans for 10 minutes until fragrant. Leave oven on.
Line a 9 x 13" brownie pan with parchment paper and lightly grease the paper and sides of the pan. Arrange graham crackers in a single layer in prepared pan, filling in any holes with smaller graham cracker rectangles.
Combine sugar, butter, and cream in a medium-sized heavy saucepan and bring to a boil over medium heat, stirring occasionally. Remove from heat, and stir in vanilla (the mixture will bubble up) and the toasted pecans. Pour butter mixture over crackers, spreading to evenly coat.
Bake the pan in the oven for 10-12 minutes or until lightly browned and bubbly all over.
While cooling, melt the chocolate chips on the stove in a glass bowl over a pot of water at medium heat. Stir constantly until completely melted. Pour the chocolate over the caramel-pecan layer and tip the pan back and forth until evenly coated (it may not cover the entire thing evenly but we like that...hey, some people may not want a chocolate piece...crazies). Sprinkle immediately with sea salt and put in the fridge until cooled and firm.
Remove bark from the pan using the parchment over-hang and cut into bars/bark using a sharp knife. Store in the fridge, covered, to ensure the chocolate doesn't get too soft.