Preheat the oven to 350 degrees. Grease and line a 9x9 inch pan with parchment paper.
Set up a double boiler using a bowl over a pot of boiling water, and melt together the butter and 1 1/2 cups chocolate chips until melted and smooth. Alternatively, you can do this in the microwave (at 30 second intervals), but you need to be careful to not burn the chocolate. Stir in the sugar, vanilla, and instant coffee. Set aside to cool for a minute.
In a small bowl whisk the eggs for 1 minute until bubbly on top. Stir the eggs into the chocolate mix. Add the flour, cocoa powder, and baking powder. Stir until just combined. Stir in the remaining 1/2 cup chocolate chips.
Evenly spread the mixture into the prepared baking pan. Bake for 25-30 minutes or until the brownies are just set. Let cool (or not) and dust with powdered sugar. Enjoy!