Melt milk chocolate.  Cool to at least 98°.  Whip cream until it holds a soft peak.    Add whipped cream to the warm chocolate, a little at a time, stirring with a spoon.  When all chocolate is added, stir in salt and vanilla.  Chill in refrigerator until mixture is firm but not stiff (5-20 minutes).  Beat with a spoon only until fluffy.  Do not overbeat. 
 After the truffle mixture has chilled 5-20 minutes, pack mixture into a pastry bag filled with a coupler without the ring.  Pipe a layer of  caramel in the chocolate-lined candy mold then pipe a layer of truffle on top. Finish piece by covering truffle mixture with chocolate.
Recipe and image taken with permission from Autumn Carpenter's Book, All About Candy Making. All rights reserved.