Preheat your oven to 425 F (skip this step if doing an overnight ferment).

Lightly coat the bottom of an 8-inch springform pan with cooking spray. Line the pan (horizontally) with 1 sheet of non-stick parchment paper. Place a second sheet of parchment paper on top (vertically) to create an X. Smooth out the bottom and sides to fit the pan- it won’t look perfect. Tip: I scrunch up my parchment paper first, which seems to fit better.

Add the softened cream cheese and sugar to the bowl of a stand mixer. Mix until smooth and fluffy, about 1-2 minutes on medium speed. Scrape down the sides of the bowl with a rubber spatula.

With the machine on low, add the eggs one at a time.

Combine the heavy cream and sourdough starter in a separate bowl. Mix with a fork to dissolve the starter (just like you would do when making sourdough bread dough). It’s easier to incorporate into the batter this way.

With the machine on low, gradually pour the the heavy cream mixture into the stand mixer bowl. When finished, turn off the machine. Gently mix the batter with a rubber spatula to ensure the texture is cohesive (check the very bottom of the bowl- sometimes a bit of cream cheese will get stuck down there!).

Pour the batter into your lined pan. Note: at this point, if you are fermenting the batter overnight, cover the pan with an inverted dinner plate and place it into the fridge. In the morning, let it sit at room temperature until the cheesecake batter reaches 69-72 F before baking. This will take several hours. Use a digital thermometer to check.

Place the cheesecake pan onto a baking sheet. Bake on the center rack for approximately 43-45 minutes. The cheesecake is done when it puffs up like a soufflé, is golden brown on the surface, and has a very wobbly center. There will be cracks on the surface too.

Remove the baking sheet from the oven. Cool the cheesecake at room temperate for 2 hours. Transfer to the fridge to cool for another 2-3 hours (for a creamy, pudding like consistency) or 6 hrs-overnight (for a firm, creamy and fluffy consistency). Note: If opting for a longer chill time, I do recommend letting the cheesecake sit out at room temperate for at least 1 hour, or until a digital thermometer reads 55-60 F before serving.