Place the dark chocolate chunks and butter in a microwavable bowl. Heat for 30 seconds at a time. Once out of the microwave, mix until smooth with your Mini Whisk. Set aside.
In a Mixing Bowl, whisk together eggs and sugar until light and fluffy (about 2 minutes). Whisk in your cooled chocolate preparation. Then, add the Vanilla Extract, ground coffee and flour. Mix until all incorporated.
Using a spatula fold the chocolate chips and chopped hazelnuts into your preparation.