Remove ice-cream from the freezer and allow to soften slightly on the bench so that its soft to scoop out. Take a cannoli shell and stuff small scoops of ice cream into each one. Place each stuffed individual shell into the freezer as you go (otherwise they will melt). When all 12 shells are stuffed, leave them in the freezer to set for 30 minutes.
In the meantime, place the chocolate buttons in a small glass bowl or microwave safe container and melt in 30 second bursts, mixing each time until the chocolate is melted and smooth. In another small bowl, place the nuts.
Remove one cannoli at a time from the freezer and dip each end of the cannoli first into the melted chocolate and then straight into the crushed mixed nuts. Immediately place back into the freezer and continue with the remaining cannoli.
Freeze for another hour and then they are ready to serve and enjoy!