Preheat and Prepare: Set your oven to 350°F. Grease a 9 × 9-inch baking dish, line it with parchment paper, and lightly butter the paper to prevent sticking.
Melt Butter and Chocolate: Over low heat, combine the butter and 2 cups of the chocolate chips in a medium saucepan. Stir continuously until the mixture is smooth and fully melted. Remove from the heat and let it cool for about 15 minutes.
Mix Wet Ingredients: In a large mixing bowl, whisk together the eggs, sugar, instant coffee granules, oil, and vanilla extract until combined. Gradually pour in the cooled chocolate mixture, whisking until fully incorporated. Set aside.
Prepare Dry Ingredients: In a separate bowl, mix the flour, cocoa powder, baking powder, and salt. Slowly fold the dry mixture into the wet ingredients using a spatula. Stir just until everything is evenly combined—avoid overmixing.
Transfer to Pan: Pour the batter into the prepared baking dish, smoothing it out evenly. Sprinkle the remaining ½ cup of chocolate chips over the top for extra decadence.
Bake to Perfection: Place the dish in the preheated oven. Bake for 35 to 37 minutes if you prefer fudgy brownies, or closer to 40 minutes for softer, cake-like brownies. Test the center with a knife or toothpick; for fudgy brownies, it should come out with some moist crumbs, while soft brownies will leave just a slight residue.
Cool and Serve: Allow the brownies to cool until they are nearly room temperature. Once cooled, cut them into squares and serve.