Preheat the oven to 325° F

Line a 9x9 or 8x8 baking pan with parchment paper. Spray paper with non-stick spray and set aside.

In a small saucepan over medium heat, melt butter.

Once melted, add sugar and stir for 1-2 minutes until sugar is dissolved.

Sift in the cocoa powder, stir. 

Remove from heat and let in cool for about 10 minutes.

Pour into a large bowl. And add eggs one at a time, mixing well.

Add the vanilla and coffee. Stir.

Add the flour, cornstarch, and salt. Mix until flour is incorporated.

Fold in the chocolate chunks and pour into prepared pan.

Bake for 25-35 minutes or the center is set. Remember they will set more when cool. (The toothpick test doesn't work well on these brownies because of the chocolate chunks.)

Allow to cool completely before removing from pan and cutting.