In a medium bowl, whisk together flour, baking soda, salt, and espresso powder.
In a large bowl, beat butter, brown sugar, and granulated sugar until light and fluffy.
Add eggs one at a time and mix well.
Stir in vanilla extract.
Gradually add dry ingredients into wet ingredients and mix until just combined.
Fold in chocolate chips and optional chocolate chunks.
Cover dough and chill for 30 minutes for thicker cookies.
Preheat oven to 350°F (177°C).
Line baking sheets with parchment paper.
Scoop dough onto prepared baking sheets.
Bake for 10–12 minutes until edges are lightly golden and centers remain soft.
Allow cookies to cool before serving.