I'm not sure who Marie is but she makes some damn good fudge.
Melt all ingredients except peanut butter in a saucepan or double boiler. Stir to prevent scorching.
After everything is well mixed, add peanut butter and stir to mix. If it is too runny, add sugar and/or cocoa. If it is too thick, add more rice/soy milk.
Grease a small pan with margarine. Pour mixture into pan and chill.