For the fudge mixture combine sugar, margarine and milk in a heavy saucepan and bring to a rolling boil, stirring constantly. Continue boiling for 5 minutes over medium heat, and continue stirring. Remove from heat and add chocolate wafers and stir until melted. Add marshmallow cream and vanilla and transfer to a bowl, beating the mixture until blended. 3. Pour into a greased 8x8 pan. Chill the fudge in the fridge until it hardens, then cut into squares and enjoy!