In a large mixing bowl, using a hand mixer or stand mixer, beat together butter and both sugars until creamy. Once creamy, add in eggs, and vanilla. Beat until smooth.

In a medium sized bowl, whisk together flour, baking soda, baking powder, and salt.

Slowly add dry ingredients to wet ingredients until all combined and dough forms.

Stir in chocolate chips and chopped chocolate bar.

Split the dough in half and lay out two large pieces of plastic wrap. Add half of the dough to the plastic wrap and form into log shape, using hands or plastic wrap to roll into a log, until around 16 inches x 3 inches. Repeat this for the other half of the dough and wrap tightly in plastic wrap.

Store in fridge for at least 4 hours or overnight (or freezer for longer).

When ready to bake, preheat oven to 375F and line baking sheet with parchment paper. Slice cookies into 1/2 inch pieces and place on baking sheet.

Bake for 9-11 minutes or until slightly golden brown. Let cool on wire cookie rack. Sprinkle with sea salt.