Preheat oven to 350ºF(177ºC)
Line the bottom of an 8” cake pan or a 3” tall 6” cake pan (or spring form pan of either size) with a cutout of round parchment paper. Spray the pan and its edges liberally with non-stick spray.
In a large bowl, beat half of the cream cheese with the sugar, egg, and cornstarch until super creamy. Beat in the remaining cream cheese until fully combined.
While pouring the heavy cream in a stream into the cream cheese mixture, beat the batter until the heavy cream is just combined.
Bake the cake for 110 minutes or until the center barely jiggles and has an ivory to golden caramelized top.
Allow cake to cool in pan for at least four hours. Release the cake from the pan, and chill in the refrigerator overnight before serving.