Prepare filling: Mix dry ingredients. Add milk and egg yolks. cook over low heat, stirring constantly unti thick. Add butter and vanilla. Set aside. Mix bottom layer ingredients well. Put about 2/3 of it in the bottom of pie shell. Prepare meringue by whipping egg whites and adding sugar gradually. Pour filling on top of bottom layer. Top with meringue. Sprinkle reserved peanut butter mixture on top of meringue. Bake at 325 degrees until light brown - about l0 minutes.