Boil your 4 cups of water and pour into a glass baking dish on the bottom rack in the oven.
Pour half of the cheesecake filling over the par-baked crust. If using, layer with the diced peaches (focus more on the outer ⅔ than pouring them right in the middle). Pour the other half of the filling over top. If not, just pour all of the batter into the springform pan.
Gently top the cheesecake with the sautéed peaches and top evenly with the remaining crumble.
Place the cheesecake on a baking sheet on the middle rack in the oven. Bake for 65-75 minutes. You'll know the cheesecake is done when the edges are set but the center jiggles slightly and the crumble is golden. It should seem not quite done.
Turn off the oven and crack the door, letting the cheesecake cool for about 30 more minutes in the oven. Then take the cheesecake out to cool for an hour at room temperature.
Once cooled, place the cheesecake in the fridge overnight to finish setting.
When cheesecake is set, remove the springform pan, slice, serve, and enjoy!