Preheat oven to 350 degrees F and prepare a baking sheet with parchment paper.

In a large stand mixer, combine the butter and white sugar. Beat for 3-5 minutes until light yellow and fluffy.

Add the eggs and vanilla and continue to beat together until everything is incorporated. Scrape down the sides periodically.

Add the flour, cocoa powder, baking soda and salt and combine until all the dry ingredients are just incorporated.

Mix in the chopped peppermint bark.

Using a 2 tbsp cookie scoop, place 12 cookies onto the prepared baking sheet. Sprinkle the top of each one with a touch of the fleur de sel and place the baking sheet into the oven. Bake cookies for 10 minutes. Remove from oven and transfer to a cooling rack until they are completely cooled. Serve immediately.