Begin by melting 1 cup of unsalted butter in a medium saucepan over medium heat. Stir frequently for 5–7 minutes until the butter turns a deep golden brown and emits a nutty aroma. Remove it from heat and set aside to cool for about 10 minutes.

In a large mixing bowl, whisk together 2 cups of all-purpose flour, 1 teaspoon of baking soda, 1/2 teaspoon of salt, 1 teaspoon of espresso powder, and 2 teaspoons of Vietnamese cinnamon.

Once the browned butter has cooled, transfer it to a large bowl and mix in 1/2 cup of granulated sugar and 3/4 cup of dark brown sugar. Beat until well combined. Next, add in 1 room temperature egg and 2 teaspoons of vanilla extract, mixing until smooth and shiny.

Gently fold the flour mixture into the wet ingredients using a spatula. Mix just until combined, being careful not to overmix.

Stir in 1 cup of dark chocolate chips, ensuring they are evenly distributed throughout the dough. Cover the bowl with plastic wrap and refrigerate the dough for at least 45 minutes.

Preheat your oven to 350°F (177°C) while the dough chills. Line two baking sheets with parchment paper. Use a cookie scoop to drop rounded tablespoons of dough onto the sheets, spacing them about 2 inches apart.

Bake for 14–16 minutes or until the edges are golden and the centers look set.

After baking, allow the cookies to rest on the baking sheets for 10 minutes. Then, move them to a cooling rack to cool completely before enjoying.