While your cheesecake is baking and/or cooling, start the whipped cream layer.
In a large mixing bowl, add 2 cups of the heavy cream and beat on low speed for 2 minutes. Add the powdered sugar and increase the speed to medium-high and continue to beat it until it is thick with just lightly stiff peaks. Do not overbeat.
In a medium to large double boiler, heat the remaining ½ cup of heavy cream with the white chocolate. Stir until the chocolate has completely melted and the mixture is smooth. Remove from the heat and set aside.
In a small dish, add the unflavored gelatin and sprinkle 1 tablespoon of water over the gelatin. Once the gelatin has absorbed the water, heat for 20 seconds in the microwave and then fully incorporate into the white chocolate/cream mixture.
Add about 1 cup of the whipped heavy cream to the white chocolate mixture and thoroughly combine. Gently fold another cup of whipped heavy cream into the white chocolate mixture, and repeat until all of the whipped cream has been used. It is important to be gentle while folding in the whipped cream so you don't deflate your white chocolate whipped cream.
Transfer half of your white chocolate whipped cream to a large piping bag fitted with a large star tip, and store the piping bag and bowl of whipped cream in the refrigerator until your cheesecake has cooled to room temperature.
When your cheesecake has cooled to room temperature, you can top it with the half of the white chocolate whipped cream that is not in the bag. The layer will be over 1" thick. Smooth it out to create a nice finish.
The cake will need to cool in the refrigerator lightly covered (with venting) for at least 8 hours, but overnight is best.