Make fudge frosting: In a medium bowl,(I like the Kitchen Aid stand mixer,) cream the butter and shortening. Add in the vanilla until just mixed. Add the cocoa powder and beat well. Slowly add in the confectioners sugar and the half and half, alternating. If too thick, add another tsp. or 2 of half and half. If too thin, add a little more confectioners sugar. Beat on high for 3-4 minutes until fluffy and glossy. Frost cooled cupcakes.