Brown the Butter: In a saucepan over medium heat, melt 1 cup of unsalted butter, stirring occasionally. Cook for 5–7 minutes until golden brown. Remove from heat and let cool for 10 minutes.

Mix Dry Ingredients: Whisk together 2 ½ cups of all-purpose flour, 1 teaspoon of baking soda, ½ teaspoon of salt, 2 teaspoons of espresso powder, and 2 teaspoons of Vietnamese cinnamon in a mixing bowl.

Combine Wet Ingredients: In a large bowl, mix the cooled brown butter, ¾ cup granulated sugar, ½ cup dark brown sugar, and ½ cup light brown sugar. Add 1 large egg and 2 teaspoons of vanilla extract, mixing until smooth.

Incorporate Dry Ingredients: Gently fold the dry ingredients into the wet mixture. Add 1 cup of dark chocolate chips and fold until evenly distributed.

Chill Dough: Cover the dough with plastic wrap and refrigerate for 45 minutes.

Prepare to Bake: Preheat your oven to 350°F (177°C) and line two baking sheets with parchment paper.

Shape and Bake Cookies: Scoop dough balls onto the lined baking sheets, spacing them 2 inches apart. Bake for 14–16 minutes until the edges are lightly browned.

Cool: Let the cookies rest on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.