Preheat your oven at 180c and line an 8 inch square pan with parchment paper.
To a small bowl, add the melted butter and 150gr dark chocolate chips. Whisk until it's combined and a smooth texture. You can place this in the oven if the butter is not hot enough for another 10 seconds. Set aside once it's mixed.
In a large bowl, add the eggs and sugars. Whisk 2-3 minutes, until it's light and fluffy.
Add the melted butter mixture on the eggs & sugars and stir until it's combined.
Fold in the cocoa powder, vanilla extract, flour & espresso powder.
Lastly, fold in the extra dark chocolate chips and pour the batter in your prepared pan, smoothing it out to create an even layer.
Bake this for 25-30 minutes or until a toothpick comes out clean from the center.
Once you remove it from the oven, allow it to cool down for 1-3 hours. Slice and enjoy! 💕