1
Make cacao pastry: rate butter, set aside.
In a big bowl add pastry flour with cocoa powder ground toasted hazelnuts, grated butter, and salt. Mix between your hands until combined. Add muscovado sugar, egg and mix lightly. Transfer the dough to a counter and knead. Once the dough is homogenous, roll it between two Teflon sheets into 0,11 inches (3 mm). Let sit between two sheets over a baking tray in the fridge for 2 hours or overnight.