Step 1

Line a 13x9 inch pan with aluminum foil, allowing excess foil to hang over both ends.  Grease generously.

Step 2

Add sugar, margarine and evaporated milk to a medium size saucepan. Heat over medium heat, stirring constantly.

Step 3

Bring the mixture to a rolling boil for 5 minutes; continue to stir constantly. Remove from heat.

Step 4

Stir in chocolate chips until completely melted. Add marshmallow cream, walnuts and vanilla. Stir until completely incorporated.

Step 5

Working quickly, pour into the prepared 13x9 inch pan. Let cool completely before cutting, several hours if possible.

Step 6

Peel off foil. Cut into bite-sized pieces.