Step 1

Preheat oven to 350 degrees. Line two baking sheets with parchment paper and set aside.

Step 2

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

Step 3

Add butter and sugars to a large bowl and beat with an electric mixer until light and fluffy, about 2 minutes. Add in the espresso, egg, and vanilla and continue beating until combined and smooth, about 1 minute more. Gradually beat in the dry ingredients until just combined, being careful not to overmix the batter. Fold in the chocolate chunks. Let chill in the refrigerator for at least 30 minutes.

Step 4

Using a spoon or 1-ounce ice cream scooper, roll chilled dough into 1-inch balls. Place on prepared baking sheets at least 2-inches apart. Note, these crisp yet chewy cookies will spread a good amount during baking. Sprinkle with a pinch of flaky salt.

Step 5

Bake until just beginning to turn golden brown around the edges, about 10 minutes. Let cool slightly on sheet trays. Transfer to a wire rack to cool completely. Cookies may appear soft at first but will firm up as they cool. Serve with a cold glass of milk or dunked into your favorite coffee drink!