Break Oreos into small chunks. Spread on bottom of 13" x 9" pan. Cut the 1/2 gallon vanilla ice cream into slices & place over the oreos. Using a large piece of plastic wrap, lay it on the ice cream & press down gently so cookies stick to bottom of ice cream. Freeze.
Put all "Middle Layer - Fudge Sauce" ingredients in a pan on the stove top. Over medium heat stir untill all ingredients melt & mix together. Raise heat to medium high, stirring until it comes to a boil. Reduce heat & simmer while stirring till the sauce begins to thicken, about 5 minutes. Remove from heat & cool to room temperature.
Remove ice cream layer from freezer & remove plastic wrap. Spread with fudge sauce & return to freezer until set. Remove again from freezer. Frost with the whip topping & sprinkle with the peanuts. Press down lightly so peanuts stick to the topping. Return to freezer. When serving let set 10 minutes before cutting.