Mix pudding and 3 cups of milk in a large bowl, stirring with a whisk until thickened. Refrigerate for about 5 minutes to get a good pudding consistency. Fold in cool whip.

Place graham 5-6 graham crackers in a large bag. Gently crush with the back of a wooden spoon or spatula.

Fill the bottom of a mason jar with enough graham cracker crumbs to create a visible layer.

Top graham cracker layer with a layer of pudding mixture. Add another layer of graham cracker crumbs followed by pudding mixture. Repeat until your jar is full ending with a pudding layer. Put jars in the refrigerator while you prepare the frosting.

In a heavy saucepan, bring 1/4 cup of milk to a boil stirring frequently with a whisk. Whisk in cocoa and sugar and boil for 1-2 minutes, whisking constantly. Turn heat to low and whisk in butter and vanilla. Pour into the jars to create the chocolate top. Refrigerate for at least an hour or until chocolate is set.