Chocolate Fudge

We didn't have a lot of luck with the fudge this year.   I usually make mint chocolate, this year I tried by adding some mint Lindt (which is yummy by itself) it wasn't quite what I usually do.  I discovered that I need a new thermometer.  While it worked fine with my PB fudge it wasn't working with my toffee or chocolate fudge.  ???    I also did the spoon test and the cold water test so it wasn't so bad.  I just went with my gut.  It was definately edible!  
This is the recipe I used this year.  Aunt Teen's Creamy Chocolate Fudge.  I used a mix of all dark chocolate, no milk and added the marshmallow after the other ingredients had all melted/combined.  I also left out the nuts since it was mint.