In a microwaveable bowl (or a sauce pot on the stove) combine one portion of the heavy cream with the sugar and heat until the sugar dissolves.
Add this to the chocolate and cornsyrup and butter in a large microwaveable bowl (or simply add all of those ingredients to the pot on the stove, being very careful not to scorch the chocolate. You will be wise to switch to a Double Boiler to avoid burning your delicate chocolate. Or just use the microwave like I do.) But whatever why you choose, you will be melting slowly all of these ingredients to smooth.
The second portion of heavy cream will be reserved for later to adjust the consistency of the fudge icing.
In the Kitchen Aid Mixer fitted with the paddle attachment add the sifted confectioners sugar and let it mix on low speed and then pour in the melted chocolate/butter/cornsyrup mixture. Mix on low speed until combined, then increase to medium-hight to smooth out any lumps.
At this point you will add the second reserved portion of heavy