In the bowl of a stand mixer fitted with the whisk attachment, beat cream cheese at medium-high speed for about 1 minute, until smooth and creamy. Add sugar, cornstarch, and salt; beat until well combined, scraping down the sides as needed.
32 oz cream cheese, 1 ½ cups sugar, 3 tbsp cornstarch, 1 tsp salt
Replace the whisk with the paddle attachment. Beat in eggs and egg yolk one at a time on low speed, scraping down the bowl after each addition. Mix in vanilla, heavy cream, and sour cream until smooth and creamy. Fold in mini chocolate chips.
4 eggs, 1 egg yolk, 1 tbsp vanilla extract, ⅓ cup heavy cream, 3 tbsp sour cream, 1 cup mini chocolate chips
Pour the filling into the pre-baked crust. Use an offset spatula to smooth it into an even layer. Place the pan on the middle rack, directly over the boiling water, and bake for 1 hour 10 minutes, or until the top is set with a slight jiggle in the center.
When done, turn off the oven and allow the cheesecake to cool with the door cracked open for 1 hour. Then, transfer to the counter and cool at room temperature for another hour. Run a knife around the edges, remove from the springform pan, and refrigerate (uncovered) for at least 4 hours, preferably overnight.