Preheat oven to 350 degrees.
Add butter to a small saucepan and cook over medium heat, stirring constantly, until melted. Alternately, melt in the microwave. (Optional step for extra caramel-y flavor: Brown the butter! Keep cooking after the butter has melted. The butter will foam and bubble as it cooks. Once the liquid becomes golden brown remove from the heat and add to the bowl of a stand mixer and let cool for 2 minutes.)
Add the brown sugar, white sugar, and espresso powder to the butter and beat until well combined.
Beat in the vanilla and egg until just combined.
Gradually pour in the flour, baking soda, and salt and mix until just combined.
Stir in the chocolate chips by hand, reserving a few to press onto the tops of the cookie dough, if desired.
Portion into 9 large balls of dough and place on a large baking sheet. Dot the tops with the remaining chocolate chips.
Bake for 11 minutes exactly. Cookies will still be slightly underdone when you remove them from the oven. Do not overbake. Let sit on baking sheet for 5 minutes before removing to a cooling rack or eating.