Melt the salted butter in the microwave, add the espresso powder and let cool for 2-3 minutes.
In a large mix together all the dry ingredients: all-purpose flour, baking soda, salt.
Once the butter has cooled, add the white sugar, and brown sugar, and let sit for about five minutes.
Add the eggs and vanilla to the mixture and mix on medium speed for another 3-4 minutes. The batter should be light-colored and fluffy at this point.
Add in the dry ingredients and mix well until all the dry mixture is combined with the wet ingredients just until combined. Don't overmix.
Add in the chocolate chunks and fold into the rest of the batter.
Divide the batter into equal balls of dough (I use an ice cream scooper to help). The dough usually makes about 16-18 cookies, depending on the size.
Place mixture in the fridge for at least 2 hours (ideally overnight).
Pre-heat oven to 325F degrees.
On a cookie sheet lined with parchment paper or a silicone mat, place cookie dough balls at least 1.5 inches apart.
Place cookie sheet in the oven and bake for 12-16 minutes. The sides should start to brown on the sides but the center will look soft.
Remove from oven, and rap the cookie sheet on the counter to get that rustic cookie look.
Leave in the cookie sheet to cool for at least 20 minutes.
The cookies will be too soft when they are fresh from the oven and will harden as they cool