Preheat the oven to 325 degrees fahrenheit. Prepare a 10-inch springform pan by spraying with cooking spray.

In a medium bowl, mix the graham cracker crumbs, sugar, melted butter, and salt together. This should resemble damp sand.

Pour the crumb mixture into the prepared springform pan and press evenly into the pan. You can use the bottom of a flat glass or a flat measuring cup to really press it in well and get a nice, even crust.

Bake for 10 minutes. Allow to cool completely.

Add the softened cream cheese to the mixing bowl of a stand mixer and beat with a paddle at medium/high speed for about 1 minute. Scrape down the sides and bottom of the bowl and beat for another minute or so, until very smooth..

Add the sugar and sour cream and mix at medium/low speed until just combined. Scrape the bowl again and mix again for 30 seconds.

Add the lime juice, eggs, vanilla, and key lime zest and beat on low speed until combined, about 30 seconds-1 minute. Scrape the bowl again. Beat until just combined. At this point the batter should be smooth and fairly runny.

Using 18 inch heavy-duty aluminum foil, wrap the outside of your springform pan with 4 sheets of foil. You can use regular foil, but it may take a couple more sheets to ensure the water does not get into your pan.

Place the wrapped pan in a deep roasting pan. You can alternatively use a baking sheet, so long as the sides are about 2 inches deep.

Using very hot water, add water to the baking sheet until there is about 1 ½ inch of water around the springform pan. With the rack in the lower 3rd of the oven, carefully move the pan into the oven.

Bake at 325 degrees fahrenheit for 1-1 ½ hours. After about an hour of baking, check the cheesecake’s consistency. A slight jiggle of the pan (while still in the oven) should tell you if it’s ready or needs more time. The cheesecake should be only slightly jiggly, but not liquid. If it still seems very liquidy, give it 15 more minutes and check it again.

Once the cheesecake has only a slight jiggle, turn the oven off but leave the cheesecake in the oven for another hour or so, until the oven has cooled down. Resist the temptation to open the oven during this time! The purpose of this step is to allow the cheesecake to cool slowly as the oven cools. Doing this will prevent it from cracking, as one of the biggest reasons cheesecakes crack is the drastic temperature change going from the hot oven into the much cooler kitchen.

Once the oven and the cheesecake are cooled, remove from the oven and carefully remove the foil lining the pan. Cover and chill in the fridge for at least 6 hours.