Place brown sugar, milk, vegetable shortening and salt in a saucepan.
Bring slowly to a full rolling boil, stirring constantly, and boil 1 min.
Remove; beat until lukewarm.
Add vanilla; beat until thick enough to spread.
The mixture may still be warm.
If frosting becomes too thick, add a little cream.
Add nuts; spread on cake.
Frosts top of 8" x 8" x 2" cake.