Preheat your oven to 335°F and line a 9-inch baking pan.
Melt the butter, 1 ounce of semi-sweet chocolate, and 3 ounces of dark chocolate in a microwave-safe bowl. Use 20-second increments, stirring in between. Be careful not to overheat.
While that's melting, whisk eggs and sugar in a standing mixer at medium-high speed until you get a light, thick, and ribbony mixture.
Gently fold the melted chocolate and butter mixture into the eggs and sugar.
Mix the instant coffee with hot water and fold it in gently.
Sift in flour, cocoa powder, and salt, then fold them in.
Finally, add 2 ounces of chocolate chips and fold them in.
Pour the batter into the lined pan. Add more chocolate on top if you desire.
Bake for 20-25 minutes.
Let them cool, cut, and get ready to enjoy!