Instructions

1. Preheat the oven to 350F degrees.
2. Melt butter in a saucepan over medium heat. After a couple of minutes, the butter will begin to foam and turn brown on the bottom of the saucepan. Stir the butter to prevent burning and remove from heat and soon as the butter gives off a nutty aroma. Immediately transfer the butter to a bowl to prevent burning. Let cool for 5 minutes.
3. In a medium bowl, combine the flour, baking soda, espresso powder and salt; set aside.
4. With an electric mixer, mix the cooled butter and sugars until thoroughly blended. Beat in the egg, egg yolk, vanilla, and yogurt until thoroughly combined. Add the flour mixture to the egg mixture and beat on low-speed just until combined. Stir in the chopped chocolate.
5. At this point you can refrigerate the dough for an hour or so as it makes the cookies spread less but honestly, you don’t have to. I’ve done it both ways with great success!
6. Drop dough by the heaping tablespoon onto a lined cookie sheet about 2 inches apart. Sprinkle with a bit of seat salt if desired.
7. Bake the cookies 10 minutes or until the edges of the cookies begin to turn golden brown. They will look a bit underdone in the middle, but will continue to cook once out of the oven. Cool the cookies on the sheets for 3-5 minutes. Remove the cookies from the baking sheets and transfer to a wire rack to cool completely.
8. These cookies freeze beautifully or can be stored in an airtight container on the counter for up to 5 days.