Preparation

1. Combine crumble ingredients together in food processor until sandy mixture forms. Press half the mixture into a 9" pie pan. Reserve other half. Refrigerate both pie crust and topping until ready to use.
2. In a small bowl whisk together 2 cups milk, egg yolks, cornstarch, salt, and vanilla extract. Set aside.
3. Pour remaining milk, butter, and sugar into small saucepan. Heat over medium stirring often until small bubbles appear around the edges of the pan. This means the milk has been scalded.
4. Whisk in cornstarch mixture slowly. Reduce heat to medium low and cook until bubbles form across pan, stirring occasionally. Cook until thick, uniform mixture is achieved. Remove from heat and fold in peanut butter. Pour into metal bowl and chill in refrigerator for 1-2 hours. If there are any lumps in filling run a stick blender through it just before transferring to shell.
5. Pour filling into peanut-crumb-lined pie pan and level with back of spoon. Cover with Cool Whip and then sprinkle remaining peanut crumbles on top. Chill in refrigerator for at least 1 hour before serving. Cut into slices to serve.