Grease the bottom of a 9-inch springform pan and line with parchment paper. Pre heat the oven to 350°F. Set aside an additional pan for a water bath.
In a large bowl, beat 1 package of cream cheese, ⅓ cup granulated sugar and all the cornstarch on low speed until combined - about 3-4 minutes. Scrape down the sides and bottom of the bowl and add the next package of cream cheese. Beat on medium-low until smooth and creamy, scrape down the sides and repeat until all the cream cheese is incorporated.
On medium speed, add the remaining sugar and vanilla extract. Add the eggs one at a time. Scrape down the sides of the bowl again and beat for 30 to 45 seconds on medium speed until mixture appears light and airy, but don't over mix.
Pour batter in the spring form pan over the parchment paper liner. Place the spring form pan in a shallow pan and fill the outside pan half way up the springform pan with hot water. Bake the cheesecake until golden brown, about 45 minutes to 1 hour, until the center just barely giggles and the outside springs to the touch.
Carefully remove the cheesecake from the water bath and transfer to a wire rack to cool (still in the springform pan). Once cool completely, refrigerate overnight in the springform pan.
To remove from the pan, run a hot knife along the outside. Carefully unlatch the springform pan and remove the sides. Don't forget to peel off the parchment paper while building the cake.