Shake the butter with the sugar. Put the chocolate in a water bath with coffee melt. In a large bowl mix the puree of chestnuts with melted chocolate and add the butter cream. Mix well and poured into the greased muffin ceramic shapes. Align the surface and put parfait in the freezer for about 12 hours. Cut orange slices. Put a slice of orange on the plate for serving, and on top a parfait. Leave at room temperature for 30 minutes before serving. Garnish with grated chocolate in large pieces.