I just made this recipe and it's very old but very easy. Not sure if its the one your looking for, but it is fantastic.
1 12 oz.pkg of Nestle's semi sweet choc. bits.
1 can of condensed milk (not evaporated)
2 squares of baking chocolate
1 cup of walnuts (chopped but left in big pieces)
1 tsp. vanilla
Melt everything together. Mix well.
Pour into a 8 or 9" square pan lined with WAX paper. Chill.
When ready, peel off wax paper and cut into squares.
Good Luck and I hope this could be the one.