Preheat the oven to 350 degrees F. Line a 9x13 inch pan with parchment paper.In the microwave, melt together the butter and 1 1/2 cups chocolate chips (stir at 30 second intervals) until melted and smooth. Stir in the sugar, vanilla, and instant coffee. 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 28-30 minutes or until the brownies are just set. Let cool (or not) and dust with powdered sugar. Enjoy!