Finely shred the kunafa pastry and toast it in a skillet over medium heat until golden brown, about 5-7 minutes. Mix with pistachio spread and chill for 10 minutes.

Brown the butter in a medium saucepan, then whisk in brown sugar, egg, and optional coffee until smooth.

Sift together cocoa powder, flour, baking soda, and salt. Fold into the wet mixture until just incorporated.

Flatten a portion of the dough, place a pistachio ball in the center, and encase it with the dough.

Preheat oven to 180°C (350°F). Bake cookie balls for about 10-12 minutes and cool for 20-25 minutes.