In a small saucepan, melt the butter over medium heat. Cook the butter, stirring occasionally, until brown bits form at the bottom of the pan. Remove from heat and allow to cool slightly. Go make your breakfast, read the paper, have some coffee or something of those sorts.

Preheat the oven to 350ºF. Line two baking sheets with parchment paper.

In a medium bowl, whisk together flour, baking soda and salt. Set aside for a moment.

In a large bowl, combine the browned butter (still slightly warm) with cocoa powder and whisk until very smooth. Whisk in sugars, vanilla extract, buttermilk and coffee. Gradually stir in the flour mixture until no streaks of flour remain. Stir in the chocolate chips.

Drop dough in 1-inch balls onto prepared baking sheet, leaving about two inches between cookies to allow for spreading. Sprinkle the cookies with fleur de sel.

Bake for 10-12 minutes, until cookies are set around the edges. Cool for 2-3 minutes on a baking sheet, then transfer to a wire rack with a spatula to cool completely. Oh baby, these are amazing hot, warm, you name it.