In a heat-proof container, whisk together the gelatin powder and 1 cup of boiling water until the crystals are completely dissolved, about 2 minutes. Stir in the 1/2 cup of cold water, then set the mixture aside to cool slightly at room temperature.

In a large mixing bowl, beat the softened cream cheese, sugar, and vanilla extract together on medium speed until the mixture is smooth and free of lumps.

Gently fold the thawed whipped topping into the cream cheese mixture using a rubber spatula until the color is uniform and no streaks remain.

Spread the cream cheese mixture evenly into the bottom of the graham cracker crust, smoothing the top with your spatula.

Slowly pour the cooled gelatin mixture over the back of a spoon onto the cream cheese layer to prevent it from breaking the surface.

Place the pie in the refrigerator and chill for at least 3 to 4 hours, or until the gelatin layer is firm to the touch.

Slice with a sharp, warmed knife to ensure clean, crisp edges for serving.