1-First Step: Brown the butter. Heat unsalted butter over medium heat until fully melted, then reduce to medium-low. Keep cooking until it turns golden brown with brown bits. Pour the browned butter into a mixing bowl and cool it for 10 minutes.

2-Second Step: Whisk the dry ingredients. In a separate bowl, whisk together all-purpose flour, baking soda, salt, espresso powder, and Vietnamese cinnamon. Set this dry mix aside so it is ready when you start combining wet ingredients.

3-Third Step: Combine butter and sugars. Once the butter is cooled, mix in the light brown sugar, dark brown sugar, and granulated sugar. Whisk until the mixture looks smooth and the sugars blend in.

4-Fourth Step: Add the egg and vanilla. Add the room temperature egg and whisk until smooth. Stir in the vanilla extract and make sure the mixture looks consistent.

5-Fifth Step: Fold in dry ingredients gently. Add the dry ingredients to the wet mixture and fold just until the flour starts to disappear. Important: stop while some flour is still visible, then finish mixing enough to combine.

6-Sixth Step: Add the chocolate chips. Gently incorporate the dark chocolate chips so they distribute evenly. Avoid overmixing, because that can make cookies tougher.

7-Seventh Step: Chill the dough. Cover the dough and refrigerate for 45 minutes. Chilling helps control spreading and boosts flavor, especially from the Vietnamese cinnamon.

8-Eighth Step: Prep the oven and baking sheets. Preheat the oven to 350°F (177°C). Line baking sheets with parchment paper to prevent sticking and support even browning.

9-Ninth Step: Portion and space the dough. Scoop dough using a 2 tablespoon portioner. Place dough balls about 2 inches apart so they have room to spread.

10-Final Step: Bake, rest, and cool. Bake 14 to 16 minutes, until the edges are light brown. Rest the cookies 10 minutes on the baking sheet, then move them to a cooling rack for another 10 minutes as the centers firm up.