Turn off your oven, place a wooden spoon on your oven door to keep it slightly ajar, and leave your cheesecake to cool for 30 minutes. Remove from the oven, place on a cooling rack and run a knife around the rim to loosen it (leaving the rim on). Let cool completely, cover with aluminum foil, and refrigerate overnight or for 8 hours. Over a small metal bowl and with a whisk attachment, whip the heavy cream and sugar until soft peaks form. Spread the whipped cream on top of your chilled cheesecake