In a double boiler, gently melt the 4 ounces of chopped unsweetened chocolate over simmering water. Stir occasionally until the chocolate is completely melted and smooth.
In a mixing bowl, combine the melted chocolate with the 14 ounces of sweetened condensed milk. Mix well until fully incorporated. This rich mixture will form the base of your filling.
Take 8 ounces of the Cool Whip and gently fold it into the chocolate and condensed milk mixture. Use a spatula to ensure you maintain the light and airy texture. Be careful not to overmix!
Pour the chocolate filling into your prepared peanut butter cookie pie crust, spreading it evenly with the spatula. The crust will add a delightful nutty flavor that complements the chocolate perfectly.
Cover the pie with plastic wrap and refrigerate for at least 4 hours, or until the filling is set. This chilling step is crucial for achieving that perfect slice.
Once the pie is firm, remove it from the refrigerator and top it with the remaining 4 ounces of Cool Whip. You can get creative with this step by adding swirls or peaks for an impressive presentation.
Slice the pie into wedges and serve chilled. You can garnish with chocolate shavings or crushed peanuts for an extra touch. Enjoy your Easy Chocolate Cool Whip Pie!