Grease and line a pan with parchment paper. Set aside.
Preheat the oven to 350°F / 180°C.
To a medium saucepan, add the chocolate, butter, coffee powder, and half of the cocoa powder. Melt everything over medium heat and whisk continuously so as not to burn the chocolate. Keep whisking until everything has melted.
Sift the remaining cocoa powder with the flour and baking soda. Set aside.
In a large bowl, mix the sugar and salt together. Add the eggs all at once and beat on high with an electric mixer for about 5 minutes. The mixture should be thick like cake batter.
Add the melted chocolate mixture to the egg mixture and beat until well combined.
Gently fold in the dry ingredients until you don’t see any more white streaks. Don’t overmix.
Pour the batter into the prepared pan and spread evenly on top.
Bake for about 15- 25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs on it. The longer you bake them, the drier and cakier they'll be.
Allow it to cool completely to room temperature, then lift out of the pan.
Cut into squares and store in an airtight container in the refrigerator for up to 5 days.