Preheat oven to 350 degrees.

Whisk flour, sugar and salt together.

Melt butter and pour over dry ingredients. Work with a wooden spoon to mix until there is no dry flour.

Line a 9X13 pan with foil in both directions ensuring that it overlaps all sides.

Crumble the cookie mix into the pan and press into an even layer. Prick the layer over the entire surface with a fork.

Bake at 350 until top is light brown and firm, about 25 to 30 minutes.

Remove from oven and use a flat spatula to press down firmly and compact the entire layer while still hot.

Let cool completely.

Put sweetened condensed milk in saucepan and add brown sugar, corn syrup, butter (cut into pieces), salt and heavy cream.

Heat over medium heat until mixture boils stirring occasionally. Continue to boil until mixture reaches 236° to 239° (about 16 to 20 minutes).

Pour immediately over cookie base and smooth layer. Let cool completely before proceeding.

Finely chop 6 oz of the bittersweet chocolate and place in microwaveable bowl. Finely Grate the remaining 2 oz of bittersweet chocolate and set aside.

Take the 6 oz of finely chopped chocolate and Microwave at 50% power for 15 seconds, remove and stir. Repeat until chocolate is JUST melted. About 1 to 2 minutes.

Stir the remaining 2 oz of grated bittersweet chocolate into the melted chocolate and stir until it is completely melted. If needed, place in microwave at 50% power for 5 seconds and stir until JUST melted.

Pour immediately over Carmel layer and spread with an offset spatula. OPTIONAL, Press pecan halves or chopped pecans into chocolate layer before it sets.

Place in refrigerator until chocolate layer is JUST set. Remove entire bar from pan using foil to lift out. Score and cut with serrated knife into smaller bars.